Friday, November15, 2019

Volvo Penta Md2010 20 30 40 Workshop Manual


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Workshop Manual           A
                Engine   2(0)

MD2010, MD2020, MD2030, MD2040
                                            Workshop Manual
                                                          Marine engines
            MD201OA/B/C                     MD202OA/B/C                    MD203OA/B/C             MD204OA/B/C

Technical data                                                              Repair instructions
I njection pump                                                        9    I njection pump                               54
Wear tolerances                                                       15    Adjustment of injection angle                 55
Tightening torque                                                     17    Adjustment of speed                           57
                                                                             Feed pump                                    58
                                                                             Fuel filter                                  59
Special tools                                                         18
                                                                             Bleeding of fuel system                      59
                                                                             I njector                                    60
Presentation                                                                Checking of injector                          61
Description of engine                                                 19
                                                                            Cooling system
Engine body                                                                 Description                                   62
Description                                                           24    Repair instructions
Repair instructions:                                                        Refrigerants                                  63
Cylinder head                                                         25    Checking of refrigerant level                 64
Valves. valve mechanism .........................................     28    Cleaning                                      65
Cylinder block, pistons. connecting rods                              34    Circulation pump                              66
Timing gears                                                          40    Sea water pump                                66
Camshaft                                                              44    Replacing the thermostat                      67
Crank mechanism                                                       46    Checking the thermostat                       67

Lubricating system                                                          Electrical system

Description                                                           51    Description                                   68
Repair instructions                                                         I mportant info                               70
Oil pump                                                              52    Starting with auxiliary battery               71
Replacing the oil filter                                              52    Troubleshooting, glow plug, charging system   72
Cleaning the oil channels .........................................   52    Alternator                                    74
                                                                            Starter motor                                 76
                                                                            Electrical components                         78
Fuel system                                                                 Wiring diagram                                80
Description                                                           53    Extra equipment                               87

                                  The data given in this Workshop Manual refers in general to
                                  engines in both A, B and C versions unless otherwise stated.

                                        Safety Precautions
     I ntroduction
  This Workshop Manual contains technical specifica-
                                                               0    Check that the warning or information labels on
                                                                    the product are always clearly visible. Replace
  tions, descriptions and instructions for the repair of the        l abels which have been damaged or painted

  Volvo Penta products or product types described in the
  Table of Contents. Check that you have the correct
  Workshop Manual for your engine.
  Before starting work on the engine read the "Safety Pre-          Engines with turbocharger ( TC ): Never start the
  cautions", "Genera! Information" and "Repair Instruc-             engine without installing the air cleaner ( ACL )
  tion" sections of this Workshop Manual carefully.                 filter. The rotating compressor in the Turbo can
                                                                    cause serious personal injury. Foreign objects

  I mportant
                                                                    entering the intake ducts can also cause me-
                                                                    chanical damage.
  I n this book and on the product you will find the follow-
  i ng special warning symbols.
         WARNING! Possible danger of personal injury,                Never use start spray products or similar when
Q        extensive damage to property or serious me-
         chanical malfunction if the instructions are not
                                                                     starting the engine. They may cause an explo-
                                                                     sion in the inlet manifold. Danger of personal in-
         followed.                                                  jury.

         I MPORTANT! Used to draw your attention to
         something that can cause damage or malfunc-
                                                               IL   Avoid opening the filler cap for engine coolant
         tions on a product or damage to property.
                                                                    system (freshwater cooled engines) when the
Note! Used to draw your attention to important informa-             engine is still hot. Steam or hot coolant can
      tion that will facilitate the work or operation in            spray out. Open the filler cap slowly and release
      progress.                                                     the pressure in the system. Take great care if a
                                                                    cock, plug or engine coolant line must be re-
Below is a summary of the risks involved and safety                 moved from a hot engine. Steam or hot coolant
precautions you should always observe or carry out                  can spray out in any direction.

when operating or servicing the engine.

         I mmobilize the engine by turning off the power            Hot oil can cause burns. Avoid getting hot oil on
         supply to the engine at the main switch (switch-           the skin. Ensure that the lubrication system is
         es) and lock it (them) in the OFF position before          not under pressure before carrying out any work.
         starting work. Set up a warning notice at the en-          Never start or operate the engine with the oil fill-
         gine control point or helm.                                er cap removed, otherwise oil could be ejected.

         As a general rule all service operations must be      I&   Stop the engine and close the sea cock before
         carried out with the engine stopped. However,              carrying out operations on the engine cooling

         some work, for example certain adjustments re-
         quire that the engine is running when they are
         carried out. Approaching an engine which is op-
         erating is a safety risk. Loose clothing or long           Only start the engine in a well-ventilated area. If
         hair can fasten in rotating parts and cause seri-          operating the engine in an enclosed area en-
         ous personal injury. If working in proximity of an         sure that there is exhaust ventilation leading out
         engine which is operating, careless movements              of the engine compartment or workshop area to
         or a dropped tool can result in personal injury.           remove exhaust gases and crankcase ventila-
         Take care to avoid contact with hot surfaces (ex-          tion emissions.
         haust pipes, Turbocharger (TC ), air intake pipe,
         start element etc .) and hot liquids in lines and
         hoses on an engine which is running or which
         has just been stopped. Reinstall all protective
         parts removed during service operations before
         starting the engine.

     Always use protective glasses or goggles when
     carrying out work where there is a risk of splin-
                                                            O    Ensure that rags soaked in oil or fuel and used
                                                                 fuel or oil filters are stored safely. Rags soaked
     ters, grinding sparks, acid splashes or where               i n oil can spontaneously ignite under certain cir-
     other chemicals are used. The eyes are ex-                  cumstances. Used fuel and oil filters are envi-
     tremely sensitive, an injury could result in blind-         ronmentally dangerous waste and must be de-
     ness!                                                       posited at an approved site for destruction
                                                                 together with used lubricating oil, contaminated

                                                                 fuel, paint remnants, solvent, degreasing agents
                                                                 and waste from washing parts.
     Avoid getting oil on the skin! Repeated expo-
     sure to oil or exposure over a long period can
     result in the skin becoming dry. Irritation, dry-
     ness and eczema and other skin problems can                 Never expose a battery to naked flame or elec-
     then occur. Used oil is more dangerous than                 trical sparks. Never smoke in proximity to the
     fresh oil from a health aspect. Use protective              batteries. The batteries give off hydrogen gas
     gloves and avoid oil soaked clothes and shop                during charging which when mixed with air can
     rags. Wash regularly, especially before eating.             form an explosive gas - oxyhydrogen . This gas
     There are special skin creams which counteract              i s easily ignited and highly volatile. Incorrect
     drying out of the skin and make it easier to clean          connection of the battery can cause a single
     off dirt after work is completed.                           spark which is sufficient to cause an explosion
                                                                 with resulting damage. Do not shift the connec-
                                                                 tions when attempting to start the engine (spark
                                                                 risk) and do not lean over any of the batteries.
     Many chemicals used on the product (for ex-

     ample engine and transmission oils, glycol,
     gasoline and diesel oil), or chemicals used in
     the workshop (for example degreasing agents,                Always ensure that the Plus (positive) and Mi-
     paint and solvents) are dangerous to health.                nus (negative) battery leads are correctly in-
     Read the instructions on the product packaging              stalled on the corresponding terminal posts on
     carefully! Always follow the safety precautions             the batteries. Incorrect installation can result in
     for the product (for example use of protective              serious damage to the electrical equipment. Re-
     mask, glasses, gloves etc .). Make sure that other          fer to the wiring diagrams.
     personnel are not exposed to hazardous chemi-

     cals, for example in the air. Ensure good ventila-
     tion in the work place. Follow the instructions
                                                                 Always use protective goggles when charging
     provided when disposing of used or leftover
                                                                 and handling the batteries. Battery electrolyte
                                                                 contains sulfuric acid which is highly corrosive.

                                                                 Should the battery electrolyte come into contact
                                                                 with unprotected skin wash off immediately us-
      Excercise extreme care when leak detecting on              i ng plenty of water and soap. If battery acid
     the fuel system and testing the fuel injector jets.         comes in contact with the eyes, immediately
      Use eye protection. The jet from a fuel injector           flush with plenty of water and obtain medical as-
      nozzle is under extremely high pressure and                sistance at once.
     has great penetrative energy, so the fuel can

     penetrate deep into the body tissue and cause
     serious personal injury. Danger of blood poison-
                                                                 Turn the engine off and turn off the power at the
     i ng.
                                                                 main switch(es) before carrying out work on the

                                                                 electrical system.

     All fuels and many chemical substances are
     flammable. Do not allow naked flame or sparks
                                                                 Clutch adjustments must be carried out with the
     i n the vicinity. Fuel, certain thinner products and
                                                                 engine stopped.
     hydrogen from batteries can be extremely flam-
     mable and explosive when mixed with air.
     Smoking is not to be permitted in the vicinity!
     Ensure that the work area is well ventilated and
     take the necessary safety precautions before
     starting welding or grinding work. Always en-
     sure that there are fire extinguishers at hand
     when work is being carried out.

                                     General Information

About this Workshop Manual
This Workshop Manual contains technical specifica-                The service intervals and maintenance proced-
tions, descriptions and instructions for the repair of the         ures recommended by Volvo Penta must be fol-
following engines in standard format: MD2010 ,                     l owed.
MD2020 , MD2030 , MD2040 . This Workshop Manual
can show operations carried out on any of the engines             Only Volvo Penta Genuine Spare Parts intended
li sted above. As a result the illustrations and pictures in       for the certified engine version must be used.
the manual that show certain parts on the engines, do
not in some cases apply to all the engines listed. How-           Service of injection pumps, pump settings, and
ever the repair and service operations described are in            i njectors, shall always be conducted by an aut-
all essential details the same. Where they are not the             horised Volvo Penta workshop.
same this is stated in the manual and where the differ-
ence is considerable the operations are described sep-            The engine must not be rebuilt or modified in any
arately. The Engine Designations and Engine Number                 way, with the exception of the accessories and
can be found on the product plate. Please always in-               service kits that Volvo Penta has developed for
clude both the engine designation and the engine                   the engine.
number in all correspondance .
                                                                  I nstallation adjustments on exhaust pipes and
The Workshop Manual is produced primarily for the use              supply air channels for the engine compartment
of Volvo Penta workshops and service technicians. For              (ventilation channels) must not, without due care,
this reason the manual presupposes a certain basic
                                                                   be conducted since this can influence exhaust
knowledge of marine propulsion systems and that the
user can carry out the mechanical/electrical work de-
scribed to a general standard of engineering compet-              Seals must not be broken by unauthorised per-
ence.                                                              sonnel.
Volvo Penta products are under a continual process of
development and we therefore reserve all rights regard-              I MPORTANT! Use only Volvo Penta Genuine
i ng changes and modifications. All the information in         Q     Spare Parts. The use of non genuine parts
this manual is based on product specifications avail-                i mplies that AB Volvo Penta will no longer
able at the time the book was published. Any essential               assume responsibility for compliance of the
changes or modifications introduced into production or               engine with the certified versions. All types
updated or revised service methods introduced after the              of damage or costs resulting from the use of
date of publication will be provided in the form of Ser-
                                                                     non genuine Volvo Penta spare parts for the
vice Bulletins.
                                                                     product in question will not be regulated by
                                                                     Volvo Penta.
Replacement parts
Replacement parts for the electrical and fuel systems
are subject to various national safety requirements, for
example the United States Coast Guard Safety Regula-
tions. Volvo Penta Original Spare Parts meet these
specifications. Any type of damage which is the result of
using replacement parts that are not original Volvo Pen-
ta replacement parts for the product in question will not
be covered under any warranty or guarantee provided
by AB Volvo Penta.

Certified engines
For engines certified for national and regional environ-
mental legislation the manufacturer undertakes to en-
sure compliance with such environmental requirements
for both new engines and engines is use. The product
must comply with the approved example on certifica-
tion. For Volvo Penta as the manufacturer to be able ac-
cept responsibility for the compliance of engines in use
with the set environmental requirements, the following
requirements for service and spare parts must be ful-

                  Repair instructions and methods
The working methods described in the Workshop Man-           Our joint responsibility
ual apply to work carried out in a workshop. The engine
has been removed from the boat and is installed in an        Every engine consists of many systems and compon-
engine fixture. Unless otherwise stated reconditioning       ents that work together. If one component deviates from
work which can be carried out with the engine in place       the technical specifications this can have dramatic con-
follows the same working method.                             sequences on the environmental impact of the engine
                                                             even if it is otherwise in good running order. It is there-
Warning symbols used in this Workshop Manual (for full       fore critical that the stated wear tolerances are ob-
explanation of the symbols refer to the section; "Safety     served, that systems which can be adjusted are cor-

                                                             rectly set up and that only Volvo Penta Original Parts
                                                             are used on the engine. The stated service intervals in

                                                             the Maintenance Schedule must be followed.
                                                             Some systems, such as the components in the fuel sys-
                                                             tem, require special expertise and special testing equip-
                                                             ment for service and maintenance. Some components
Note!                                                        are factory sealed for environmental and product spe-
                                                             cific reasons. Under no circumstances attempt to ser-
are not in any way comprehensive since it is impossible      vice or repair a sealed component unless the service
to predict every circumstance under which service work       technician carrying out the work is authorized to do so.
or repairs may be carried out. Volvo Penta AB can only
i ndicate the risks considered likely to occur as a result   Bear in mind that most of the chemicals used around
of incorrect working methods in a well-equipped work-        boats are harmful to the environment if used incorrectly.
shop using working methods and tools tested by Volvo         Volvo Penta recommends the use of bio-degradable
Penta AB.                                                    degreasing agents for all cleaning of engine compon-
                                                             ents unless otherwise stated in the Workshop Manual.
 All operations described in the Workshop Manual for         When working onboard a boat make a special point of
 which there are Volvo Penta Special Tools available         preventing oil, waste water from washing components
 assume that these tools are used by the service techni-     entering the bilges ; i nstead remove all such waste for
 cian or person carrying out the repair. Volvo Penta Spe-    safe disposal at an approved site for destruction.
 cial Tools have been specifically developed to ensure
 as safe and rational working methods as possible. It is
therefore the responsibility of the person or persons us-    Tightening torques
 i ng other than Volvo Penta Special Tools or approved
Volvo Penta working methods (as described in a Work-         The correct tightening torques for critical joints which
shop Manual or Service Bulletin), to acquaint them-           must be tightened using a torque wrench are listed un-
selves of the risk of personal injury or actual mechan-      der "Technical Specifications - Tightening Torques "
ical damage or malfunction that can result from failing to   and stated in the method descriptions in the Workshop
 use the prescribed tools or working method.                 Manual. All tightening torques apply to cleaned threads,
                                                             bolt heads and mating surfaces. Tigthening torques
I n some cases special safety precautions and user in-       stated are for lightly oiled or dry threads. Where grease,
structions may be required in order to use the tools and     l ocking or sealing agents are required for screwed
chemicals mentioned in the Workshop Manual. Always           j oints this is stated in both the operation description and
follow these precautions as there are no specific in-        i n "Tightening Torques". Where no tightening torque is
structions given in the Workshop Manual.                     stated for a joint use the general tightening torques ac-
By following these basic recommendations and using           cording to the tables below. The tightening torques stat-
common sense it is possible to avoid most of the risks       ed are a guide and the joint does not have to be tight-
i nvolved in the work. A clean work place and a clean        ened using a torque wrench.
engine will eliminate many risks of personal injury and
engine malfunction.
Above all when working on the fuel system, engine lub-       Dimension Tightening torque
rication system, air intake system, Turbocharger unit,
                                                                           Nm            ft.Ibs
bearing seals and seals it is extremely important to ob-
serve the highest standards of cleanliness and avoid         M5              6             4
dirt or foreign objects entering the parts or systems,       M6             10              7
since this can result in reduced service life or malfunc-
tions.                                                       M8             25             18
                                                             M -1 0         50            37
                                                             M12            80            59
                                                             M14           140           103

Tightening torque with Protractor tight-                     Make sure that mating surfaces are dry and free from
                                                             oil, grease, paint and anti-corrosion agent before apply-
ening (angle tightening)
                                                             i ng sealant or locking fluid. Always follow the manufac-
Tightening using both a torque setting and a protractor      turer's instructions for use regarding temperature range,
angle requires that first the recommended torque is ap-      curing time and any other instructions for the product.
plied using a torque wrench and then the recommended         Two different basic types of agent are used on the en-
angle is added according to the protractor scale. Ex-        gine and these are:
ample: a 90 protractor tightening means that the joint is
tightened a further 1/4 turn in one operation after the      RTV agent (Room temperature vulcanizing). Used for
stated tightening torque has been applied.                   gaskets, sealing gasket joints or coating gaskets. RTV
                                                             i s visible when a part has been disassembled; old RTV
                                                             must be removed before resealing the joint.

Lock nuts                                                    The following RTV agents are mentioned in the Service
                                                             Manual: Loctite 574, Volvo Penta P/N 840879-1, Per-
Do not re-use lock nuts that have been removed during        matex No. 3, Volvo Penta P/N 1161099-5, Permatex
dissassembly operations as these have reduced ser-           Nr 77. Old sealant can be removed using methylated
vice life when re-used - use new nuts when assem-            spirits in all cases.
bling or reinstalling. For lock nuts with a plastic insert
                                                             Anaerobic agents. These agents cure in an absence of
such as Nylock the tightening torque stated in the ta-
                                                             air. They are used when two solid parts, for example
ble is reduced if the Nylock nut has the same head
                                                             cast components, are installed face-to-face without a
height as a standard hexagonal nut without plastic in-
                                                             gasket. They are also commonly used to secure plugs,
sert. Reduce the tightening torque by 25% for bolt size
                                                             threads in stud bolts, cocks, oil pressure switches and
8 mm or larger. Where Nylock nuts are higher, or of
                                                             so on. The cured material is glass-like and it is therefore
the same height as a standard hexagonal nut, the
                                                             colored to make it visible. Cured anaerobic agents are
tightening torques given in the table apply.
                                                             extremely resistant to solvents and the old agent cannot
                                                             be removed. When reinstalling the part is carefully de-
                                                             greased and then new sealant is applied.
Strength classes                                             The following anaerobic agents are mentioned in the
Bolts and nuts are divided up into different classes of      Workshop Manual: Loctite 572 (white), Loctite 241
strength; the class is indicated by the number on the        (blue).
bolt head. A high number indicates stronger material,
for example a bolt marked 10-9 indicates a higher
                                                             Note: Loctite is the registered trademark of Loctite Corparation ,
strength than one marked 8-8. It is therefore important      Permatex the registered trademark of the Permatex Corporation.
that bolts removed during the disassembly of a bolted
j oint must be reinstalled in their original position when
assembling the joint. If a bolt must be replaced check in
the replacement parts catalogue to make sure the cor-
rect bolt is used.

A number of sealants and locking liquids are used on
the engines. The agents have varying properties and
are used for different types of jointing strengths, oper-
ating temperature ranges, resistance to oil and other
chemicals and for the different materials and gap sizes
i n the engines.
To ensure service work is correctly carried out it is im-
portant that the correct sealant and locking fluid type is
used on the joint where the agents are required.
I n this Volvo Penta Workshop Manual the user will find
that each section where these agents are applied in
production states which type was used on the engine.
During service operations use the same agent or an al-
ternative from a different manufacturer.

    Safety rules for fluorocarbon rubber
    Fluorocarbon rubber is a common material in seal
    rings for shafts, and in O-rings, for example.
When fluorocarbon rubber is subjected to high tem-
peratures (above 300C/572F), hydrofluoric acid
can be formed, which is highly corrosive. Skin con-
tact can give severe chemical burns. Splashes in
your eyes can give severe chemical burns. If you

breathe in the fumes, your lungs can be permanently

      f     WARNING! Be very careful when working on
            engines which have been exposed to high tem-
            peratures, e.g . overheating during a seizure or
            fire. Seals must never be cut with an oxyacet-
            ylene torch, or be burned up afterwards in an
            uncontrolled manner.

         Always use gloves made of chloroprene rubber
          (gloves for handling chemicals) and protective

         Handle the removed seal in the same way as
          corrosive acid. All residue, including ash, can be
          highly corrosive. Never use compressed air to
          blow anything clean.

         Put the remains in a plastic box which is sealed
          and provided with a warning label. Wash the
          gloves under running water before removing
The following seals are probably made from fluoro-
carbon rubber:

Seal rings for the crankshaft, camshaft, intermediate

O-rings irrespective of where they are installed.
O-rings for cylinder liner sealing are almost always
made from fluorocarbon rubber.
Note that seals which have not been subjected to
high temperature can be handled normally.

                                                  Technical data
Engine designation                                              MD2010           MD2020             MD2030            M D2040
Number of cylinders                                             2                3                  3                 3
Cylinder diameter                                               67 mm            67 mm              75 mm             84 mm
                                                                (2.637 in)       (2.637 in)         (2.952 in)        (3.307 in)
Stroke length                                                   64 mm            64 mm              72 mm             90 mm
                                                                (2.519 in)       (2.519 in)         (2.834 in)        (3.543 in)
Swept volume, total                                             0.45 litres      0.68 litres        0.95 litres       1.50 litres
                                                                (27.46 )   (41.49 )     (57.97 )    (91.53 )
Power, see sales literature
I dling speed                                                   850 25 rpm      850 25 rpm        850 25 rpm       850 25 rpm
Deregulation speed/high idling                                  3900 25 rpm     3900 25 rpm       3900 25 rpm      3900 25 rpm
Compression ratio                                               23.5:1           23.5:1             23:1              22:1
Compression pressure with starter motor speed                   >3000 kPa        >3000 kPa          >3000 kPa         >3000 kPa
                                                                (>435 psi)       (>435 psi)         (>435 psi)        (>435 psi)
Firing order (cyl. No. 2 and 3 closest
to flywheel)                                                    1-2              1-2-3              1-2-3             1-2-3
Direction of rotation see from front                            Clockwise        Clockwise          Clockwise         Clockwise
Max. permissible angle backwards during operation               20              200                200               20
Max. side angle during operation                                30              30                30               30
Valve clearance, idle cold engine:
  i nlet and outlet                                 0.20 mm                       0.20 mm           0.20 mm           0.20 mm
                                                    (.0078 in)                    (.0078 in)        (.0078 in)        (.0078 in)
Weight, engine without oil and water                98 kg                         116 kg            129 kg            179 kg
                                                    (215.9lb)                     (255.5lb)         (284.2lb)         (394.3 Ib)
Max. permissible counter pressure in exhaust pipe.. 20 kPa                        20 kPa            20 kPa            20 kPa
                                                    (2.9 psi)                     (2.9 psi)         (2.9 psi)         (2.9 psi)

                                                                      MD2010                   M D2030               M D2040
                                                                      M D2020
Material                                                              Aluminium alloy          Aluminium alloy       Aluminium alloy
Height, total in mm                                                   59.045-59.095            65.575-65.625         87.66-87.74
                                                                      (2.324-2.326 in)         (2.581-2.583 in)      (3.451-3.454 in)
Height from gudgeon pin centre to piston top in mm                    33.045-33.095            35.575-35.625         47.66-47.74
                                                                      (1.300-1.302 in)         (1.400-1.402 in)      (1.876-1.879 in)
Piston clearance in mm:                                               0.048-0.082             0.0425-0.0665         0.038-0.072
                                                                      (.0018-.0032 in)        (.0016-.0026 in)      (.0014-.0028 in)
Front marking*, MD2010 , MD2020                                       The arrow alt. "F" mark on piston top should be turned forwards
                MD2030 , MD2040                                       The "SHIBAURA" mark in the piston should be turned forwards
* The pistons for certain engines also have an arrow in front
  of the gudgeon pin hole which should point forwards.

Piston rings
                                                                      MD2010                   M D2030               M D2040
                                                                      M D2020
Compression rings:
Number                                                                2                        2                     2
Top compression ring, height in mm                                    1.47-1.49                1.47-1.49             1.97-1.99
                                                                      (0578-.0586 in)          (.0578-.0586 in)      (.0775-.0783 in)
2nd compression ring, height in mm                                    1.47-1.49                1.97-1.99             1.47-1.49
                                                                      (.0578-.0586 in)         (.0775-.0783 in)      (.0578-.0586 in)
Oil ring:
Number                                                                1                        1                     1
Height in mm                                                          2.97-2.99                3.97-3.99             3.90-3.98
                                                                      (.01169-1177 in)         (.01562-.1570 in)     (.1535-.1566 in)

     ec nrcal data

                                                                                           MD2010                  M D2030               M D2040
                                                                                           M D2020

Piston ring gap in cylinder measured in mm,
    top compression ring                                                                   0.13-0.25               0.15-0.27             0.20-0.35
                                                                                           (.0051-.0098 in)        (.0059-.0106 in)      (.0078-.0137 in)
      2nd compression ring                                                                 0.10-0.22               0.12-0.24             0.20-0.40
                                                                                           (.0039-.0118 in)        (.0047-.0094 in)      (.0078-.0157 in)
Oil ring                                                                                   0.10-0.30               0.20-0.35             0.20-0.40
                                                                                           (.0039-.0118 in)        (.0078-.0137 in)      (.0078-.0157 in)
Piston ring clearance in groove measured in mm
    top compression ring                                                                   0.06-0.10               0.06-0.10             0.065-0.110
                                                                                           (.0023-.0039 in)        (.0023-.0039 in)      (.0025-.0043 in)
      2nd compression ring                                                                 0.05-0.09               0.05-0.09             0.013-0.035
                                                                                           (.0019-.0035 in)        (.0019-.0035 in)      (.0005-.0013 in)
      oil ring .........................................................................   0.02-0.06                0.02-0.06            0.030-0.130
                                                                                           (.0007-.0023 in)        (.0007-.0023 in)      (.0011-.0051 in)

Gudgeons pins
                                                                                           MD2010                  M D2030               MD2040
                                                                                           M D2020
Clearance, gudgeon pin - gudgeon bushing in mm                                             0.013-0.030             0.006-0.023          0.010-0.027
                                                                                           (.0005-.0011 in)        (.0002-.0009 in)     (.0003-.0005 in)
Gudgeon pin - gudgeon pin hole in mm                                                       -0.004- +0.008          -0.004- +0.006       -0.001- +0.011
                                                                                           (-.0001- +.0003 in)     (-.0001-+.0002 in)   (-.00003- +.0004 in)
Gudgeon pin diameter in mm                                                                 18.996-19.002           20.998-21.002        27.994-28.000
                                                                                           (.7478-.7481 in)        (.8266-.8268 in)     (1.1021-1.1023 in)
Gudgeon bushing's int. diameter in mm                                                      19.015-19.026           21.010-21.021        28.010-28.021
                                                                                           (.7486-.7490 in)        (.8271-.8275 in)     (1.1027-1.1031 in)
Gudgeon pin hole's diameter in piston in mm                                                18.998-19.004           20.998-21.004        27.999-28.005
                                                                                           (.7479-7481 in)         (.8266-.8269 in)     (1.1023-1.1025 in)

Cylinder head
                                                                                           M D2010                 MD2030               MD2040
                                                                                           M D2020
Height in mm                                                                               54.9-55.1               64.6-65.4            69.7-70.3
                                                                                           (2.161-2.169 in)        (2.543-2.574 in)     (2.744-2.767 in)
Valve seats (inlet outlet)
Inlet, diameter in mm                                                                      25.35-25.45             30.35-30.45          36.35-36.45
                                                                                           (.9980-1.001 in)        (1.194-1.198 in)     (1.431-1.435 in)
Outlet diameter in mm                                                                      21.85-21.95             26.85-26.95          32.35-32.45
                                                                                           (.8602-.8641 in)        (1.0570-1.0610 in)   (1.2736-1.2775 in)
Depth in mm                                                                                2.05-2.15               2.25-2.35            2.05-2.15
                                                                                           (.0807-.0846 in)        (.0885-.0925 in)     (.0807-.0846 in)

Crankshaft with bearing
                                                                       MD2010                    M D2020            M D2030             M D2040
(Replaceable bearing cups for main and
big end bearings)
Crankshaft, axial clearance in mm                                      0.1-0.3                  0.1 -0.3            0.05-0.30           0.1-0.4
                                                                       (.0039-.0118 in)         (.0039-.0118 in)    (.0019-.0118 in)    (.0039-.0157 in)
Main bearing, radial
clearance in mm, No. 1                                                 0.035-0.072              0.035-0.072        0.039-0.106          0.044-0.116
                                                                       (.0013-.0028 in)         (.0013-.0028 in)   (.0015-.0041 in)     (.0017-.0045 in)
                            No. 2                                      0.055-0.092              0.035-0.072        0.039-0.106          0.044-0.116
                                                                       (.0021-.0036 in)         (.0013-.0028 in)   (.0015-.0041 in)     (.0017-.0045 in)
                            No. 3                                                               0.055-0.092        0.039-0.092          0.044-0.102
                                                                                                (.0021-.0036 in)   (.0015-.0036 in)     (.0017-.0040 in)
                                                                                                                Technical data

Main bearing
Main bearing journals
                                                                    MD2010                           MD2020
Diameter in mm, standard, bearing journal     No. 1               42.964-42.975                   42.964-42.975
                                                                  (1.6915-1.6919 i n)             (1.6915-1.6919   i n)
                                              No. 2               45.964-45.975                   42.964-42.975
                                                                  (1.8096-1.8100 i n)             (1.8096-1.8100   i n)
                                              No. 3               -                               45.964-45.975
                                                                                                  (1.8096-1.8100   i n)
                   undersize, No. 1       0.25 mm                 42.760-42.786                   42.760-42.786
                                          (.0098 i n)             (1.6834-1.6844   i n)           (1.6834-1.6844   i n)
                                          0.50 mm                 42.510-42.536                   42.510-42.536
                                          (.0196 i n)             (1.6736-1.6746   i n)           (1.6736-1.6746   i n)
                   undersize, No. 2       0.25 mm                 45.764-45.790                   42.760-42.786
                                          (.0098 i n)             (1.8017-1.8027   i n)           (1.6834-1.6844    i n)
                                          0.50 mm                 45.514-45.540                   42.510-42.536
                                          (.0196 i n)             (1.7918-1.7929   i n)           (1.6736-1.6746    i n)
                   undersize, No. 3       0.25 mm                                                 45.764-45.790
                                          (.0098 i n)                                             (1.8017-1.8027    i n)
                                          0.50 mm                                                 45.514-45.540
                                          (.0196 i n)                                             (1.7918-1.7929    i n)

                                                                     M D2030                         MD2040
Diameter in mm, standard, bearing journal No. 1                   45.964-45.975                   67.900-67.970
                                                                  (1.8096-1.8100   i n)           (2.6732-2.6759    i n)
                                              No. 2               45.964-45.975                   67.900-67.970
                                                                  (1.8096-1.8100   i n)           (2.6732-2.6759    i n)
                                              No. 3               45.964-45.975                   67.960-67.986
                                                                  (1.8096-1.8100   i n)           (2.6755-2.6766    i n)
                   undersize, No. 1       0.25 mm                 45.854-45.934                   67.650-67.720
                                          (.0098 i n)             (1.8052-1.8084   i n)           (2.6633-2.6661    i n)
                                          0.50 mm                 45.604-45.684                   67.400-67.470
                                          (.0196 i n)             (1.7954-1.7985   i n)           (2.6535-2.6562    i n)
                   undersize, No. 2       0.25 mm                 45.854-45.934                   67.650-67.720
                                          (.0098 i n)             (1.8052-1.8084   i n)           (2.6633-2.6661    i n)
                                          0.50 mm                 45.604-45.684                   67.400-67.470
                                          (0196 i n)              (1.7954-1.7985   i n)           (2.6535-2.6562    i n)
                   undersize, No. 3       0.25 mm         :....   45.714-45.725                   67.710-67.736
                                          (.0098 i n)             (1.7997-1.8001   i n)           (2.6657-2.6667    i n)
                                          0.50 mm                 45.464-45.475                   67.460-67.486
                                          (.0196 i n)             (1.7899-1.7903   i n)           (2.6559-2.6569    i n)

Big-end bearing
Big-end bearing journals
                                                        MD2010, MD2020                MD2030                M D2040
Big-end bearing, radial clearance in mm                 0.031-0.068                   0.035-0.083           0.035-0.085
                                                        (.0012-.0026 i n)             (.0013-.0032 i n)     (.0013-.0033 i n)
Bearing journal length in mm                            15.65-16.55                   17.70-18.60           19.70-20.60
                                                        (.6161-.6515 i n)             (.6968-.7322 i n)     (.7755-.8110 i n)
Diameter in mm, standard                                34.964-34.975                 38.964-38.975         51.964-51.975
                                                        (1.3765-1.3769 i n)           (1.5340-1.5344 i n)   (2.0458-2.0463 i n)
                 undersize, 0.25 mm                     34.714-34.725                 38.714-38.725         51.714-51.725
                            (0098 i n)                  (1.3666-1.3671 i n)           (1.5240-1.5246 i n)   (2.0359-2.0364 i n)
                            0.50 mm                     34.464-34.475                 38.464-38.475         51.464-51.475
                            (.0196 i n)                 (1.3561-1.3572 i n)           (1.5143-1.5147 i n)   (2.0261-2.0266 i n)

Technical data

Big-end bearing shells
                                                                       MD2010 , MD2020                   MD2030 , MD2040
Thickness in mm, standard                                               1.484-1.497                      1.482-1.495
                                                                        (.0584-.0589 i n)                (.0583-.0588 i n)
                   oversize 0.25 mm                                     1.609-1.622                      1.607-1.620
                            (.0098 i n)                                 (.0633-.0638 i n)                (.0632-.0637 i n)
                            0.50 mm ............................        1.734-1.747                      1.732-1.745
                            (.0196 i n)                                 (.0682-.0687 i n)                (.0681-.0687 i n)

Connecting rods
                                                              MD2010, MD2020                M D2030              M D2040
Fitted with replaceable bearing shells.
Diameter, gudgeon bushing's bearing position                  21.000-21.021                 23.000-23.021        30.500-30.516
                                                              (.8267-.8275 i n)             (.9055-.9063 i n)    (1.2007-1.2014 i n)
Bearing shell's bearing position                              19.015-19.026                 21.010-21.021        28.010-28.021
                                                              (.7486-.7490 i n)             (.0827-.8275 i n)    (1.1027-1.1031 i n)
Gudgeon bushing                                               19.015-19.026                 21.010-21.021        28.010-28.021
                                                              (.7486-.7490 i n)             (.8271-.8275 i n)    (1.1027-1.1031 i n)
Axial clearance, connecting rod -crankshaft                   0.031-0.079                   0.035-0.083          0.035-0.083
                                                              (.0012-.0031 i n)             (.0013-.0032 i n)    (.0013-.0032 i n)

Timing gears
                                                             M D2010                 M D2020            MD2030          MD2040
Drive                                                        Gear wheel              Gear wheel         Gear wheel      Gear wheel
Number of bearings                                           3                       3                  3               3
Valve times:
i nlet valves open B.T.D.C                                   13
                                                                                    130                 13
close A.B.D.C                                                430                    43
                                                                                                        430            40
outlet valves open B.B.D.C                                   430                    430                 430            46
close A.T.D.C                                                130                    130                 130            10

Valve system
                                                              MD2010 , MD2020               M D2030              M D2040
Spindle diameter in mm                                       5.960-5.975                    6.94-6.95            6.955-6.970
                                                             (.2346-.2352 i n)              (.2732-.2736 i n)    (.2738-.2744 i n)
Valve disc edge in mm                                        0.925-1.075                    0.925-1.075          0.925-1.075
                                                             (.0364-.0423 i n)              (.0364-.0423 i n)    (.0364-.0423 i n)
Clearance in mm, valve spindle guide                         0.045-0.072                    0.050-0.075          0.03-0.06
                                                             (.0017-.0028)                  (.0019-.0029 i n)    (.0011-.0023 i n)
Seat angle in cylinder head                                  45
                                                                                            45 0                 45

Valve clearance in mm, cold engine                           0.20                           0.20                 0.20
                                                             (.0078 i n)                    (.0078 i n)          (.0078 i n)
Spindle diameter in mm                                       5.940-5.955                    6.94-6.95           6.94-6.95
                                                             (.2338-.2344 i n)              (.2732-.2736 i n)   (.2732-.2736 i n)
Valve disc edge in mm                                        0.925-1.075                    0.925-1.075         0.925-1.075
                                                             (.0364-.0423 i n)              (.0364-.0423 i n)   (.0364-.0423 i n)
Clearance in mm, valve spindle guide                         0.045-0.072                    0.050-0.075         0.050-0.075
                                                             (.0017-.0028 i n)              (.0019-.0029 i n)   (.0019-.0029 i n)
Seat angle in cylinder head                                  45                            450                 45
Valve clearance in mm, cold engine                           0.20                           0.20                0.20
                                                             (.0078 i n)                    (0078 i n)          (.0078 i n)

                                                                                                                                                Technical data

Valve springs                                                                 MD2010                MD2020                 MD2030                MD2040
 Length in mm (in) uncompressed                                               33(l.299)             33(l.299)              35(l.377)             35(l.377)
     with 79.4 N (58.56 ft.lbf) compression                                   -                                            30.4 (1.196)          30.4 (1.196)
     with 67.7 N (49.93 ft.lbf) compression                                   28.3 (1.114)          28.3 (1.114)                                 -

 Push rods
 Length in mm (in), total                                                     146                   146                    157                   195.8-196.2
                                                                              (5.748)               (5.748)                (6.181)               (7.709-7.724)
 Outer diameter in mm (in)                                                    6.3                   6.3                    6.3                   6.2-6.4
                                                                              (.2480)               (.2480)                (.2480)               (.2441-0.2520)

 Rocker mechanism
 Rocker shaft, diameter in mm                                                 11.65-11.67           11.65-11.67            11.65-11.67           11.65-11.67
                                                                              (.4586-.4594 in)      (.4586-.4594 in)       (.4586-.4594 in)      (.4586-.4594 in)
Clearance in mm, rocker shaft - bushing                                       0.032-0.068           0.032-0.068            0.032-0.068           0.032-0.068
                                                                              (.0012-.0026 in)      (.0012-.0026 in)       (.0012-.0026 in)      (.0012-.0026 in)

 Lubrication system
                                                                              MD2010                MD2020                 MD2030                MD2040
Oil pressure in kPa, hot engine at running speed                              150-500               150-500                150-500               150-500
                                                                              (21.7-73 lbf/in t)    (21.7-73 lbf/in z)     (21.7-73 lbf/in z)    (21.7-73 lbf/int)
Oil pressure in kPa, idling                                                   50-150                50-150                 50-150                50-150
                                                                              (7.25-22 lbf/in z)    (7.25-22 lbf/in z)     (7.25-22 lbf/in z)    (7.25-22lbf/in z)
Relief valve, opening pressure in kPa                                         294-490               294-490                294-490               245-345
                                                                              (42.6-71 lbf/in')     (42.6-71 lbf/in t )    (42.6-71 lbf/in z)    (34.4-50 lbf/in z)
Oil pump:
Clearance, inner - outer impeller                                            0.01-0.15 mm           0.01-0.15 mm           0.01-0.15 mm          0.01-0.15 mm
                                                                             (.0004-.0059 in)       (.0004-.0059 in)       (.0004-.0059 in)      (.0004-.0059 in)
Axial clearance, impeller - cover                                            0.01-0.15 mm           0.01-0.15 mm           0.01-0.15 mm          0.01-0.15 mm
                                                                             (.0004-.0059 in)       (.0004-.0059 in)       (.0004-.0059 in)      (.0004-.0059 in)
Oil quality as per API system                                                CD                     CD                     CD                    CD
Viscosity at -5 to +50C* (+23 to +122F)*                                   SAE 15W/40.            SAE 15W/40.            SAE 15W/40.           SAE 15W/40.
                                                                             SAE 20W/50             SAE 20W/50             SAE 20W/50            SAE 20W/50
Max. Oil volume incl. oil filter:
no engine tilt (version A/B)                                                 1.8 litres             3.4 litres             4.3 litres            6.4 litres
                                                                             (1.9 US quarts)        (3.6 US quarts)        (4.5 US quarts)       (6.7 US quarts)
no engine tilt (version C)                                                   1.9-litres             2.8 litres             3.5 litres            5.7 litres
                                                                             (2.0 US quarts)        (3.0 US quarts)        (3.7 US quarts)       (6.0 US quarts)
Min. Oil volume incl. oil filter:
no engine tilt (version A/B)                         1.5 litres                                     3.0 litres             3.2 litres            5.5 litres
                                                     (1.6 US quarts)                                (3.2 US quarts)        (3.4 US quarts)       (5.8 US quarts)
no engine tilt (version C)                           1.3 litres                                     2.1 litres             2.7 litres            4.5 litres
                                                     (1.7 US quarts)                                (2.2 US quarts)        (2.9 US quarts)       (4.8 US quarts)
* Note: Temperatures with stable ambient temperature.

                                                                            MD2010                 MD2020                 MD2030                MD2040
I njection sequence                                                         1-2                    1-2-3                  1-2-3                 1-2-3
Feed pump max. induction height in m (ft)                                   0.8 (2.62)             0.8 (2.62)             0.8 (2.62)            0.8 (2.62)
Feed pressure in kPa (lbf/inz)                                              15-25 (2.1-3.6)        15-25 (2.1-3.6)        15-25 (2.1-3.6)       15-25 (2.1-3.6)

I njection pump
                                                                            M D2010                M D2020                MD2030                MD2040
Start of injection, crankshaft position                                     25.5 1              25.5 +1              22.5110              21.0 10
                                                                            B.T.D.C                B.T.D.C'               B.T.D. C 3            B.T.D.C 5
                                                                                                   27.7  1             21.51              19.01
                                                                                                   B.T.D. C 2

                                                                                                                          B.T.D.C 4             B.T.D. C 6,7
Pump element, diameter in mm (in)                                           4.5 (.1771)            4.5 (.1771)            5.5 (.2165)           5.5 (.2165)
stroke length in mm (in)                                                    6(.2362)               6(.2362)               6(.2362)              7(.2755)
' up to and including engine number 5101311299                                       4
                                                                                         from engine number 510101939                             7
  from engine number 5101311300                                                      5
                                                                                         MD2040A/B product number 868748
  up to and including engine number 510101938                                        6
                                                                                         MD2040B product number 868778
Technical data

Injector                                              MD2010              MD2020           MD2030           MD2040
Opening pressure (checking)                           11.3-12.3 MPa 11.3-12.3 MPa 11.3-12.3 MPa 15.2-16.2 MPa
                                                      115-125 kp/cm 2 115-125 kp/cm2 115-125 kp/cm 2 2 155-165 kp/cm 2 2
                                                      1639-1784 lbf/in 2 1639-1784 lbf/in 2 1639-1784 lbf/in 2205-2347 lbf/in
Opening pressure (adjustment)                         11.8 MPa           11.8 MPa           11.8 MPa         15.7 MPa
                                                      120 kp/cm 2        120 kp/cm2         120 kp/cm2       160 kp/cm2
                                                      1711 lbf/int       1711 lbf/int       1711 lbf/int     2276 lbf/int
Needle valve, diameter                                3.5 mm             3.5 mm             6mm              4mm
                                                      (0.1378 in)        (0.1378 in)        (0.2362 in)      (0.1575 in)
Journal diameter                                      1 mm               1 mm               1 mm             1 mm
                                                      (0.0394 in)        (0.0394 in)        (0.0394 in)      (0.0394 in)
Jet angle                                             4                 4                 4               40

Cooling system
                                                        MD2010             MD2020          MD2030           MD2040
Type                                                                       Overpressure, closed cooling system
Fresh water system volume, approx (vers. A/B).          2.1 litres         3.0 litres       4.0 litres       6.9 litres
                                                        2.2 US quarts      3.2 US quarts    4.2 US quarts    7.3 US quarts
Fresh water system volume, approx (vers. C) ....        2.3 litres         2.9 litres       4.5 litres       6.7 litres
                                                        2.4 US quarts      3.1 US quarts    4.8 US quarts    7.1 US quarts

Thermostat, number                                      1 st               1st             1st              1 st
Thermostat begins to open at                            750 2C           75 2C        82 2C         82 2C
                                                        (167 4F)        (167 4F)     (179 4F)      (179 4F)
                   fully open at                        87C (189F)       87C (189F)    95C (203F)     95C (203F)
Thermostat valve's lifting height                       6 mm               6mm             8 mm             8 mm
                                                        (0.2362 in)        (0.2362 in)     (0.3150 in)      (0.3150 in)

Electrical system
                                                        M D2010            MD2020          MD2030           MD2040
System voltage                                          12V                12V             12V              12V
Fuses                                                   15A                15A             15A              15A
Battery capacity (starter battery)                      70 Ah              70 Ah           70 Ah            70 Ah
Glow plug:
  rated voltage                                         10.5V             10.5V            10.5V            10.5V
  current                                               6.9 A             6.9 A            6.9 A            6.9 A

                                                        M D2010           MD2020           MD2030           MD2040
Output voltage at +20C (+68F)                       14.2 0.15 V        14.2 0.15 V     14.2 0.15 V     14.2 0.15 V
Max. current                                           60 A               60 A             60 A             60 A
Power approx                                           840 W              840 W            840 W            840 W
Suppressor capacitor                                   2.2 F             2.2 hF           2.2 hF           2.2 F
Voltage regulator type                                 YV 77              YV 77            YV 77            YV 77

Starter motor
                                                        M D2010           MD2020           MD2030           MD2040
Starter motor, power approx                             0.7 kW            0.7 kW           1.2 kW           2.0 kW
Engine speed* with connected starter motor,
approx                                                  340 rpm           300 rpm          285 rpm          265 rpm

 Note: refers to engine with timing gears and at approx. +20C (+68F).

                                                                                                       Technical data

                                              Wear tolerances
                                Note: Unless otherwise stated the given values refer to all engines.

Compression pressure at starter motor speed (min. 200 rpm) ....      min. 25 kp/cm2 (355.6 lbf/int)

Piston clearance                                                     max. 0.25 mm (.0098 in)

Piston rings
Piston ring clearance in groove:
Compression rings                                                    max. 0.25 mm (.0098 in)
Oil ring                                                             max. 0.15 mm (.0059 in)
Piston ring gap in cylinder                                          max. 1.0 mm (.0393 in)

Gudgeon pins
Gudgeon pin diameter:
MD2010 . MD2020                                                     min. 18.98 mm (.7472 in)
MD2030                                                              min. 20.98 mm (.8259 in)
MD2040                                                              min. 27.98 mm (1.1015 in)
Clearance, gudgeon pin - bushing                                    max. 0.08 mm (.0031 in)
     gudgeon pin - hole                                             max. 0.02 mm (.0007 in)

Cylinder head
Distortion                                                          max. 0.12 mm (.0047 in)

Cylinder block
Distortion (top plane)                                              max. 0.12 mm (.0047 in)
Cylinder diameter
MD2010 . MD2020                                                     max. 67.2 mm (2.6456 in)
  0.2 mm (.00787 in) oversize                                       max. 67.7 mm (2.6653 in)
  0.5 mm (.01969 in) oversize                                       max. 68.2 mm (2.6850 in)
MD2030                                                              max. 75.2 mm (2.9606 in)
  0.5 mm (.01969 in) oversize                                       max. 75.7 mm (2.9803 in)
  1.0 mm (.03937 in) oversize                                       max. 76.2 mm (3.0000 in)
MD2040                                                              max. 84.2 mm (3.3149 in)
  0.5 mm (.01969 in) oversize                                       max. 84.7 mm (3.3346 in)
  1.0 mm (.03937 in) oversize                                       max. 85.2 mm (3.3543 in)

Technical data

Curvature                                                            max. 0.06 mm (.00236 in)

Connecting rods
Linearity, deviation on 100 mm (3.937 in) measured length            max. 0.15 mm (.00590 in)
Distortion on 100 mm (3.937 in) measured length                      max. 0.2 mm (.00787 in)
Axial clearance, crankshaft - connecting rod                         max. 0.7 mm (.02755 in)

Max. valve clearance*, inlet and outlet (cold engine)                max. 0.5 mm (.01968 in)
* Maximum permitted valve clearance before adjustment must be carried out

Starter motor
Commutator diameter:
MD2010. MD2020 . MD2040                                              min. 31 mm (1.2204 in)
MD2030                                                               min. 40 mm (1.5748 in)
Brush length                                                         min. 11.5 mm (.4527 in)
Brush spring tension MD2010 . MD2020 . MD2040                        min. 8.8 N (2.0 lbf)
Brush spring tension MD2030                                          min. 13.7 N (3.0 lbf)

                                                                                                         Technical data

                       Tightening torque in Nm (ft.lbf)
                                                               MD2010                  M D 2030         M D2040
                                                               M D 2020

Cylinder head*                                       -   35-40 (25.8-29.5)       50-53 (36.9-39.1)   90-95 (66.4-70.1)
Main bearing:
  top to bottom bearing cap (steel)                      25-30 (18.4-22.1)       25-30 (18.4-22.1)   50-55 (36.9-40.5)
  (aluminium)                                   ;        20-25 (14.7-18.4)       20-25 (14.7-18.4)
  Main bearing cap to cylinder block                     25-30 (18.4-22.1)       25-30 (18.4-22.1)   50-55 (36.9-40.5) **
                                                                                                     25-30 (18.4-22.1)***
Big-end bearing                                          21-26 (15.5-19.2)       30-35 (22.1-25.8)   50-55 (36.9-40.5)
End-plate/flywheel housing                               13-17 (9.6-12.5)        47-55 (34.7-40.6)   13-17 (9.6-12.5)
Flywheel housing                                         24-29 (17.7-21.4)       24-29 (17.7-21.4)   24-29 (17.7-21.4)
Flywheel                                                 70-80 (51.6-59.0)       60-70 (44.3-51.6)   60-70 (44.3-51.6)
Flexible coupling                                        9-12 (6.6-8.8)          9-12 (6.6-8.8)      9-12 (6.6-8.8)
Adapter plate for flywheel housing                       24-29 (17.7-21.4)       24-29 (17.7-21.4)   24-29 (17.7-21.4)
Suction strainer, oil pump                               9-13 (6.6-9.6)          9-13 (6.6-9.6)      9-13 (6.6-9.6)
Bottom plate                                             9-12 (6.6-8.6)          9-12 (6.6-8.6)      9-12 (6.6-8.6)
Sump                                                     9-13 (6.6-9.6)          9-13 (6.6-9.6)      9-13 (6.6-9.6)
Drain plug, sump                                         30-40 (22.1-29.5)       30-40 (22.1-29.5)   30-40 (22.1-29.5)
Timing gear casing                                       9-12 (6.6-8.6)          9-12 (6.6-8.6)      9-12 (6.6-8.6)
Crankshaft pulley                                        90-100 (66-74)          120-130 (86-96)     280-340 (206-250)
I njection pump                                          9-13 (6.6-9.6)          9-13 (6.6-9.6)      9-13 (6.6-9.6)
Bearing bracket, rocker shaft                            20-25 (14.7-18.4)       20-25 (14.7-18.4)   20-25 (14.7-18.4)
Valve cover                                              10-12 (7.4-8.6)         10-12 (7.4-8.6)     8-12 (5.9-8.6
Pressure oil pipe (cylinder block-cylinder head).        10-13 (7.4-9.6)         10-13 (7.4-9.6)     1 0-13 (7.4-9.6)
I njector                                                60-70 (44.3-51.6)       80-85 (59.0-62.7)   60-70 (44.3-51.6)
Delivery pipe                                            20-25 (14.7-18.4)       20-25 (14.7-18.4)   15-25 (11.0-18.4)
Pressure valve holder                                    35-39 (25.8-28.8)       40-45 (29.5-33.2)   40-45 (29.5-33.2)
Relief valve                                             60-70 (44.3-51.6)       60-70 (44.3-51.6)   60-70 (44.3-51.6)
Lock screw (max. fuel volume)                            20-25 (14.7-18.4)       20-25 (14.7-18.4)   20-25 (14.7-18.4)
Lock screw (speed)                                       13-17 (9.6-12.5)        13-17 (9.6-12.5)    13-17(9.6-12.5)
Glow plug                                                15-20 (11.0-14.7)       15-20 (11.0-14.7)   1512'76"(11. 0-14.7)
Oil pressure relay                                       15-20 (11.0-14.7)       15-20 (11.0-14.7)   15-20 (11.0-14.7)
Refrigerant temperature relay                            25-30 (18.4-22.1)       25-30 (18.4-22.1)   25-30 (18.4-22,1) -
Oil pressure sensor                                      15-20 (11.0-14.7)       15-20 (11.0-14.7)   15-20 (11.0-14.7)
Refrigerant temperature sensor                           15-20 (11.0-14.7)       15-20 (11.0-14.7)   15-20 (11.0-14.7)

   The tightening torque given under respective engine is the final tightening torque.
   The cylinder head should be tightened in three stages and in the correct sequence.
   See tightening torque diagram on page 32.
   Grease in the cylinder head screw threads with grease containing molybdenum disulphide.
** Hexagonal screws
   Rear cap (socket head screws)

                                        Special tools
Note. If necessary, the workshop should be equipped with 2 deep (minimum 80 mm) hexagonal sockets, 22 mm and
27mm, for removing the injectors. These sockets can be obtained from a well stocked tool supplier and are not
stocked by Volvo Penta.

                                  885224-6      Engine fixture. The tool should be supplemented with 4 pcs pin
                                                screws 479971-4, 4 pcs nuts 971095-5, 4 pcs screws 970964-3
                                                ( M10x140), 4 pcs screws 955311-6 (M8x140), 4 pcs washers
                                                960148-5 (M10), 4 pcs washers 960141-0 (M8) and the arms
                                                from engine fixture 885050-5.

                                  9992520-8     Overhaul stand

                                  856927-9      Measuring plastic (disposable item)

                                  9510060-8     Multimeter

                                  9999179-6     Key for dismantling of fuel and oil filters.

                                  885251-9      Adapter for measuring compression pressure MD2030 .

                                  885252-7      Adapter for measuring compression pressure MD2010 , MD2020
                                                and MD2040 .


   General                                                                    Design differences, engine versions
   The engines are in-line, 4-stroke, marine diesel engines                   This Workshop Manual applies to all engines MD2010-
   fitted with top valves. MD2010 has two cylinders, while                    2040 A, B, C
   MD2020 , MD2030 and MD2040 have three cylinders.                           The most important differences are:
   The engines are of the pre-chamber type and equipped
   with glow plugs which are activated before and during
   starting.                                                                  MD2010-40A =* MD2010-40B

   The engines are fitted with thermostat regulated fresh                     MD2010-40B has:
   water cooling. The cooling system is divided into a                            Unipolar electrical system
   fresh water and a sea water system. The sea water
   cools the fresh water system via a heat exchanger.                            The fly wheel cover and the transmission (reverse
   Lubricating takes place by means of an oil pressure                            gear or S-drive) are electrically insulated from the
   system where an oil pump presses oil to all the lubrica-                       engine
   tion point. The oil system is provided with a replaceable
   oil filter of the full-flow type.
                                                                              MD2010-40B = MD2010-40C
   The fuel system is protected from impurities by a re-                      MD2010-40C has:
   placeable fine filter.
                                                                                  Heat exchangers with improved cooling performan-
                                                                                   ce and extended expansion volume

                                                                                  Deeper and narrower oil sump

                                                                                  Reinforced generator mountings for 2010 and 2020

                                                                                  Common oil filter for 2010-40

    Positioning of rating plates


                                                           a,usan asseraBLY                                     vxUYeo ~x nCCOXnnxR' i0 x x.
                                                                                                        XXXXXXX XXX ( 4)
                                                                                        C.    nvvxoR nl
                                                                                                       '   n       '     m. ..
                                                                                                                            ~                   0
                                     XXXX ( 1)        XXXX (5)
                                     XXXXXXXXXX(2)                                       VOLVO XXXX (1)        XXX XXX (3)
                                     XXX XXX (3)      XXXXXXXXXX(6)
                                                      XXX XXX (7)                        PEP7TA XXXXXXXXXX (2)

                                    Engine and transmission decal                                          Engine plate

                                       1. Product designation                     5. Product designation
                                       2. Serial number                           6. Serial number
                                       3. Product number                          7. Product number
                                       4. Certification number                    8. Gear ratio


                   2    3

                                   17         16 15    14   13
                MD201OA/B & MS2L        MD2010A/B & MS2L


                                                          17               16    15           14             13
                         MD203OA/B & MS2A                               MD203OA/B & MS2A

                     1       2            3

                         MD204OA/B & MS2L

  1.   Cap for replenishing of refrigerant          13.   Sea water pump
  2.   Expansion tank                               14.   I njection pump
  3.   Relay box with fuses                         15.   Oil filter
  4.   Flexible suspension                          16.   Feed pump (with hand pump)
  5.   Starter motor                                17.   Oil cooler, reverse gear
  6.   Alternator                                   18.   Folding propeller
  7.   Oil dipstick, reverse gear/S-drive           19.   Refrigerant intake, S-drive
  8.   Cap for oil dipstick, reverse gear/S-drive   20.   Refrigerant cock (sea water), S-drive
  9.   Fuel filter                                  21.   Oil drain, S-drive
1 0.   Cap for oil replenishment, engine            22.   Zinc anode (zinc ring)*
11.    Oil dipstick, engine                         23.   MD201OA-2040A: Earthing relay (for starter motor and
12.    Air filter/Air intake                              glow plug)

                                                      Note: When running in freshwater the magnesium anode
                                                      ( magnesium ring) should be used.



      6        4        5        4
                                      17                16 15     14   13

                    MD2010-C & MS2L              MD2010-C & MS2L

               1    2       3                   78     9 12 10 11

                                           22     21

                   MD2020-C & 120S              MD2020-C & 120S



               6       4             5              4

                           MD2030-C & MS2A                                    MD2030-C & MS2A

                                               3                    7    8 12        9       10 11

       6           4         5                  4                 17                 16     15

                           MD2040-C & MS2L                                    MD2040-C & MS2L

  1.       Cap for replenishing of refrigerant          14.    I njection pump
  2.       Expansion tank                               15.    Oil filter
  3.       Relay box with fuses                         16.    Feed pump (with hand pump)
  4.       Flexible suspension                          17.    Oil cooler, reverse gear
  5.       Starter motor                                1 8.   Folding propeller
  6.       Alternator                                   1 9.   Refrigerant intake, S-drive
  7.       Oil dipstick, reverse gear/S-drive           20.    Refrigerant cock (sea water), S-drive
  8.       Cap for oil dipstick, reverse gear/S-drive   21.    Oil drain, S-drive
  9.       Fuel filter                                  22.    Zinc anode (zinc ring)*
1 0.       Cap for oil replenishment, engine
11.        Oil dipstick, engine
                                                          Note: When running in freshwater the magnesium anode
12.        Air filter/Air intake
                                                          ( magnesium ring) should be used.
1 3.       Sea water pump

                                                Engine body

Description                                                  Crank mechanism
Cylinder head                                                The crankshaft is journaled in three main bearings
                                                             ( MD2010 ), or four main bearings (other engines). The
The cylinder head is manufactured of specially alloyed       axial bearing on MD2040 consists of loose thrust wash-
cast iron. It is provided with replaceable valve seats for   ers placed at the rear main bearing. On the other en-
the inlet valves.                                            gines the rear main bearing cap is made of aluminium
The cylinder head is screwed onto the cylinder block         and serves as thrust washers. The crankshaft is statically
with screws. The tightening of the cylinder head should      and dynamically balanced and has induction hardened
be done in three stages.                                     bearing surfaces. At the front the crankshaft is fitted with
                                                             a key joint and at the rear with a flange on which the fly-
                                                             wheel is attached.

Cylinder block
The cylinder block is cast in one piece of specially al-
l oyed cast iron.

                                                             Main and big-end bearings
                                                             The main and big-end bearings consist of steel shells
                                                             li ned with bearing metal. The bearings are precision
Pistons, piston rings                                        milled and ready for installation. Two oversizes are
                                                             available as spare parts.
The pistons are manufactured of a light-weight metal al-
l oy. They are fitted with three piston rings (chromium-     Note: The thrust washers for the crankshaft's axial bear-
plated) - two compression rings and an oil ring.             i ng are not available in oversize.

The injection pump is driven from the front part of the
camshaft by means of two or three separate cams (de-         Connecting rods
pending on the number of cylinders).                         The connecting rods have I-sections. The piston bolt end
The feed pump is driven via an eccentric cam from the        is through-drilled for lubrication of the gudgeon pin.
rear of the camshaft.

Timing gears                                                 Flywheel
The timing gears consists of cylindrical gears with be-      The flywheel is screwed on a flange on the rear of the
velled cogs.                                                 crankshaft. It is statically balanced and fully processed.
The camshaft and sea water pump are driven from the          The starter ring is shrunk onto the flywheel.
crankshaft gear via an intermediate gear. The engine's       A flexible coupling with damper element of rubber is
oil pump is built into the intermediate wheel and is dri-
                                                             screwed on the flywheel. The coupling transfers the
ven via this. Regulator weights are suspended in the         force to the reverse gear/S-drive.
front edge of the camshaft gear.

                                                                                                           Engine body

Repair instructions
Cylinder head
Dismantling of cylinder head

1.   Remove both battery leads. Close the fuel cocks.

2.   Close the bottom valve and drain off the water in
     the sea and fresh water system.

3.   Release the hose to the heat exchanger from the
     sea water pump. Release the exhaust pipe from
     the exhaust hook.

                                                             Fig. 9.   Dismantling of expansion tank with heat ex-
4.   Release the thick rubber hose under the heat ex-                        1. Heat exchanger complete
     changer. (Note: the hose is filled with refrigerant).                   2. MD2010 , MD2020 : Spring
     Release the thin hose from the refrigerant pump.                        3. MD2o10, MD2020 : Thermostat

                                                             9.   Remove the expansion tank complete with heat ex-
                                                                  MD2010 , MD2020 : Remove the spring, thermostat
5.   MD2010 , MD2020 : remove the drive belt for the al-
                                                                  and rubber seal from the heat exchanger housing.
     ternator/refrigerant pump. Remove the alternator
     and clamp.

                                                             10. MD2010, MD2020 , MD2030 :
                                                                  Remove the induction manifold.
                                                                  MD2040 :
6.   Release the relay box from the heat exchanger                Remove the inlet pipe complete with air filter.
     housing and hang it up.

                                                             11. Release the delivery pipe at the injection pump
7.   Release the electric cables to the oil pressure relay       and injectors. Lift off the delivery pipes together.
     and to the refrigerant temperature relay and sensor         Protect the connections from impurities.
     (where appropriate).

8.   MD2040 : remove the cover at the front on the heat      12. Remove the nut at the top of respective injectors
     exchanger housing's right-hand side. Remove the             and lift off the fuel leak pipe.
     spacer ring, thermostat and rubber seal.

Engine body

         V                                     U

                          u                    u

                                      2        r
                          `/          3


                          CAP         2
MD2010 , -2020          M D2030           M D2040

              Fig. 10. Dismantling of injectors
     1. Injector             3. Heat shield ( MD2030 )
     2. Copper gasket        4. Insert (MD2010-2030)     Fig. 12. Dismantling of oil pressure pipe (cylinder
                                                                  block - cylinder head/rocker mechanism)

13. Unscrew the injectors. Use a long socket, 80 mm.
                                                         16. Remove the oil pressure pipe between the cylinder
      MD2010 , MD2020 , MD2030 = 22 mm
                                                             block and cylinder head (rocker mechanism on
      MD2040 = 27 mm.
      Remove the copper gaskets under the injectors.
      MD2030 : Remove the heat shields (3, Fig. 10).
                                                         17. Remove the valve cover (built together with the in-
      MD2010 , MD2020 , MD2030 : Remove the inserts          l et pipe on MD2010 , MD2020 and MD2030 ).
      (4) and the lower copper washers.

14. Release the electric cable to the glow plug. Re-
    move the conductor rail and unscrew the glow plug.

                                                         Fig. 13. Dismantling of rocker mechanism ( MD2040 )
                                                             1. Rocker mechanism 3. Valve caps
                                                             2. Pull rods

                                                         18. Release the nuts from the rockers' bearing brack-
                                                             ets. Remove the rocker mechanism (1, Fig. 13) and
                                                             pull rods (2). Remove the valve caps (3, MD2040 )
                                                             from the valve stem.

Fig. 11. Dismantling of circulation pump
                                                         19. Release the cylinder head screws in several sta-
15. MD2010 , MD2020, MD2030 : Remove the circula-            ges.
    tion pump.                                               Note: Begin in the middle of the cylinder head and
      MD2030 : Note. The pump must be released/re-           release the screws in a circle outwards.
      moved before the cylinder head is released. The        Lift off the cylinder head.
      pump can otherwise be broken. Remove the spring
      and thermostat.

                                                                                                           Engine body

Stripping of cylinder head                                  I nspection of cylinder head
                                                            The flatness tolerance for the cylinder head is max. 0.12
                                                            mm (.00472"). Check in six positions ("A-F" as per Fig.
                                                            15 and 16). Use a feeler gauge and a ruler the sides of
                                                            which are precision rubbed as per DIN 874/Normal.

             Fig. 14. Dismantling the valves
       1. Valve lock            4. Valve                           Fig. 15. Checking of cylinder head flatness
       2. Valve spring washer 5. Valve cap*
       3. Valve spring
     *MD2040 and later versions of MD2010 , 2020, 2030

1.   Remove the valves and valve springs. Press the
     springs together with a valve spring tensioner and
     remove the valve lock. Place the valves in order in
     a marked valve rack. Remove the valve stem seals.

2.   Clean all parts. Observe special care with the
     channels for oil and refrigerant.

                                                                   Fig. 16. Checking of cylinder head flatness
3.   Remove residual soot and impurities from the cylin-
     der head's sealing surfaces.
     Note: Do not use use steel brush to clean the cylin-
     der head screw threads or under the screw heads.       I f the flatness is not within the permissible tolerance the
                                                            cylinder head should be replaced. If leakage or blow
                                                            marks are confirmed it is not necessary to check for flat-
                                                            ness since the cylinder head must be replaced.
                                                            Check the valve seats and that the pin screws are tight.
                                                            For replacement of the valve seats (inlet) see next

Engine body

Replacement of valve seat                                 Grinding of valves and valve seats

                                                          1.   Use a valve spring tensioner and dismantle the
                                                               valve lock. Remove the valve spring washers,
                                                               springs and aloes. Place the parts in the correct
                                                               order in a valve rack. Remove the valve stem seals.
                                                          2.   Clean the parts.

Fig. 17. A = distance between cylinder head plane and

The valve seat should be replaced when the distance
"A" in Fig. 17 measured with a new valve exceeds
1.8 mm (.0708").
1.   Remove the old valve seat by heating it up with a
     gas jet (600-700C / 1112-1292F) diagonally
     over the seat.
     Allow the cylinder head to cool approx. 3-5 minu-             Fig. 18. Checking of valve spindle wear
     tes in the air. Carefully tap out the seat with           Diameter mm:                    I nlet        Outlet
     mandrel (check that the cylinder head is not dama-
     ged).                                                     MD2010, MD2020                  5.90 mm       5.90 mm
                                                                                               (.2322 in)    (.2322 in)
     Alternatively the valve seat can be milled out            MD2030, MD2040                  6.89 mm       6.84 mm
     (check that the cylinder head is not damaged).                                            (.2712 in)    (.2692 in)

                                                               Check the wear on the valve spindle. Measure the
                                                               diameter with a micrometer at points I, II and III as
2.   Clean the seat housing in the cylinder head care-         per Fig. 18.                     '
     fully. Check the head for cracking.
3.   Cool down the new seat with liquid nitrogen or the
     li ke to minus 60-70C (140-158F) and heat up the
     cylinder head to approx. 60-100C (140-212F).

4.   Press the seat in the head. Use a hydraulic press
     (1000-1500 kp / 2204-3307 lbf) and suitable

5.   Work the seats to the correct angle and width.                         Fig. 19. Valve disc edge

                                                          4.   Grind the valves in a valve grinding machine
                                                               Grind the sealing surface as little as possible, just
                                                               so that it is "clean". If the the valve disc edge after
                                                               grinding is less than 0.5 mm (.019 in) the valve
                                                               should be scrapped (see Fig. 19). The same ap-
                                                               plies to valves with crooked valve spindles.

                                                                                                               Engine body

5.   Check the wear on the valve guides (see "Check-        8.     Fit the seals, valves, valve springs, spring washers,
     i ng of valve guides") before the valve seats are             valve lock and valve caps. See "Assembly of cylin-
     treated.                                                      der head" on page 31.


                                                            Checking of valve guides*

              Fig. 20. Grinding of valve seat

                                                             Fig. 22. Clearance, valve - valve guide (cylinder head)
              A= Max. 2.5 mm (.0984 in)

6.   Ream or grind the valve seats (Fig. 20). Grind of      Calculate the clearance between the valve spindle and
     j ust enough material so that the valve seat has the   valve guide.
     right shape and a good mating surface.
                                                            Wear tolerances:
                                                                 I nlet valve, max. clearance         0.20 mm (.0078 in)
                                                                 Outlet valve, max. clearance         0.25 mm (.0098 in)

                                                            " Note: Since the valve guides are treated directly in the cylin-
                                                            der head this must be replaced when the clearance is exces-

                  low                                       sive, even when the valve is new.

             Fig. 21. Checking of valve seat

Replace the valve seat when the distance "A" in Fig. 21,
measured with a new valve, exceeds 1.8 mm (.0708 in).
For replacement of the valve seat (inlet) see previous

New seats are grind down so that the distance be-
t ween the cylinder head plane and the valve disc
surface "A" is:
MD2O10, MD2020: 0.70-0.90 mm (.0275-.0354 in)
MD2030, MD2040 : 0.85-1.15 mm (.0334-.0452 in)

7.   Grind in the valves with grinding paste and check
     the contact with marker dye.

 Engine body

 Checking of valve springs                                  Renovating the rocker mechanism
 Check that the springs do not show any signs of            1.     MD2O10, MD2020, MD2030: Remove the screws
 damage.                                                           at the front and rear of the rocker shaft.
                                                                   MD2040: Screw in a M8 screw in the threaded hole
                                                                   i n the front edge of the rocker shaft. Fix the screw
                                                                   head in a vice and pull out the rocker shaft (alt. a
                Max. 2.0 mm (.0787 in)                             withdrawing tool can be used).

                                                                                        r(jrq   p       -1



               Fig. 23. Checking of linearity

Place the valve springs on a level surface and check
the linearity with a st square (Fig. 23).
                                                                 Fig. 25. Dismantling of rocker mechanism (MD2040)

                                                           2.      Dismantle the rocker mechanism. Remove the
                                                                   rockers, springs and washers.

                                                           3.      Clean the parts. Observe special care with the
                                                                   rocker shaft's oil channels and oil holes in the rock-

                  Fig. 24. Spring tester

                                                                         Fig. 26. Measuring of rocker shaft
Place the spring in a spring tester and check its length
both compressed and uncompressed.
The springs should maintain the values given in "Tech-     4.     Check the wear on the rocker shaft with a microme-
nical data".
                                                                  ter (Fig. 26). Diameter min. 11.57 mm (.4555 in).

                                                                                                                    Engine body

                                                              Fitting of cylinder head

          Fig. 27. Clearance rocker - rocker shaft

                                                                          Fig. 28. Fitting of valve stem seals

5.   Check that the rocker bearing surfaces are not out-
     of-round worn.                                           1.   Press down new valve stem steals on the valve
     Calculate the clearance between the rocker and
     shaft. The clearance must not exceed 0.2 mm                   Note: MD2030 and MD2040 have different seals
     (.0078 in).                                                   for the guides for the inlet and outlet valves.
     Check that the ball pin's spherical part is not defor-
     med or worn. The threads should be undamaged
     on the pin and lock nut. The locknut should be in
     good condition.
     The mating sphere of the rockers (against the val-
     ve) must not be unevenly worn or concave. Adjust-
     ment for minor wear can be made in a grinding
     machine.                                                                                               C
     Note: MD2O10-2030. A new type of rocker (includ-
     i ng valve cap) has been introduced as from engine
        MD2010: 5101202984
        MD2020: 5101308898
        M D2030: 5101465653                                                                       00
     Only the new type of rocker is available as a spare
     part. If one or several of the older type of rocker                         2
     need to be replaced, all the rockers must be re-
                                                                               Fig. 29. Fitting of valves
     placed at once, and valve caps installed on the
     valve stems.                                                     1. Valve lock                3. Valve spring
                                                                      2. Valve spring retainer     5. Valve cap*
                                                                      4. Valve
                                                                   * MD2040 and later versions of MD2O10, 2020, 2030

                                                              2.   The valves should be fitted in the correct order. Oil
                                                                   i n the valve spindles and fit the valve in its guide.
                                                                   Place the valve spring and retainer in position and
                                                                   press the spring together with a valve spring ten-
                                                                   sioner. Fit the valve lock.
                                                                   Note: Observe care when fitting the valves and
                                                                   compressing the springs so that the valve stem
        Comparison between new and old rockers                     seals are not damaged.
1. Earlier rocker              4. The new rocker tip
2. Earlier rocker tip          5. Valve cap                   3.   Fit the valve caps when all valves are fitted. (Ap-
3. The new rocker              6. Valve                            plies to MD2040 and later versions of MD2O10,
                                                                   MD2020, MD2030 (Please refer to the note below
                                                                   item 5)).

                                                              4.   Fit new plugs if these have been removed.
6.   Oil in the rocker mechanism and fit the different

 Engine body

 Fitting of cylinder head                                       1st tightening
 1.   Clean the surface of the cylinder head and cylinder       MD2O10. MD2020                 10 Nm (7.40 ft.lbs)
      block. Remove any rust or soot from the screw ho-         MD2030                         20 Nm (14.80 ft.lbs)
      l es and threads for the cylinder head screws.            MD2040                         30 Nm (22.10 ft.lbs
2.    Fit on the new cylinder head gasket.                     2nd tightening

3.    Apply grease containing molybdenum disulphide            MD2O10, MD2020                  20 Nm (14.80 ft.lbs)
      on the cylinder head screws.                             MD2030                          35 Nm (25.80 ft.lbs)
                                                               MD2040                          70 Nm (51.70 ft.lbs)
      NOTE! The screws are surface treated and must
      not be cleaned with a steel brush.                       Final tightening

      Note: I f the cylinder head is painted the mating sur-   MD2O10, MD2020                  35-40 Nm (26-30 ft.lbs)
      faces for cylinder head screws must be free from         MD2030                          50-53 Nm (37-39 ft.lbs)
      paint, otherwise the clamping force in the screw         MD2040                          90-95 Nm (66-70 ft.lbs)
      union will be adversely affected.
4.    Check that the tubular pins (guides) are fitted in the
      block. Place the two rear cylinder head screws in
      the cylinder head and fit the head.


                                                                     Fig. 32. Fitting of the rocker mechanism (MD2040)

                                                               6.      Fit the pull rods (2), valve caps (3, MD2040 and
                                                                      l ater versions of 2010, 2020,2030) and rocker
                                                                      mechanism (1).

                                                               7.     Adjust the valve clearance as per directions on
                                                                      page 34. Fit the valve cover.

           Fig. 30. Tightening diagram, MD2O10

                                                                    Fig. 33. Fitting of oil pressure pipe (cylinder block -
Fig. 31. Tightening diagram MD2020, MD2030, MD2040                                 cylinder head / rocker mechanism)

                                                               8.     Fit the oil pressure pipe between the block and
5.    Tighten the cylinder head screws in three stages as             cylinder head (rocker mechanism on MD2040).
      per the following. See tightening diagrams Fig. 30-             Tightening torque 10-13 Nm (7.4-9.6 ft.lbs).

                                                                                                          Engine body

9.    MD2O10, MD2020: Fit the circulation pump.
      MD2030: Fit the circulation pump and thermostat
      and spring (see Fig. 35).
10. Fit the glow plug, Tightening torque: see Technical
    data. Fit the conductor rail and connect the electric                        00


                                                      1      Fig. 35. Fitting of thermostat (MD2O10, MD2020,
                                                                           MD2030) and expansion tank.

          CIRD                                        2

                                                             15. MD2O10, MD2020: Fit the rubber seal, thermostat
                                                                 (3) and spring (2) in the heat exchanger housing (1)

MD2010, -2020           MD2030            M D2040            16. Fit the expansion tank complete with heat exchan-
                                                                 ger. Connect the hoses to the heat exchanger
                 Fig. 34. Fitting of injectors                   housing and refrigerant pump. Tighten the hose
     1. Injector            3. Heat shield (MD2030)              clips.
     2. Copper gasket       4. Insert (MD2O10-2030)

11. Fit the copper gaskets, heat shields (MD2030) and
    i nserts (MD2O10-MD2030) to the injectors as per
     Fig. 34.
      Fit the injectors. Use socket L=80 mm (3.15 in),
      key width = 22 mm (MD2O10-MD2030), and 27 mm
      ( MD2040).
      Tightening torque MD2O10, MD2030, MD2040:
      60-70 Nm (44.3-51.7 ft.lbs)
      Tightening torque MD2030:
      80-85 Nm (59.0-62.7 ft.lbs).

                                                                     Fig. 36. Fitting of thermostat (MD2040)
12. Put on new copper gasket and fit the fuel leak pipe.
    Tighten the nuts and connect the return pipe.

13. Fit the delivery pipe complete. Tightening torque        17. MD2040: Fit the rubber seal, thermostat and spacer
    20-25 Nm (14.8-18.4 ft.lbs).                                 ring in the heat exchanger housing. Fit the cover
                                                                 over the thermostat.

14. MD2O10, MD2020, MD2030: Fit the induction mani-
    fold.                                                    18. Connect the electric cables to the oil pressure re-
                                                                 lay, and to the refrigerant temperature relay and
      MD2040: Fit the inlet pipe complete with air filter.
                                                                 sensor (where appropriate).

 Engine body

 19. Fit the relay box.                                       4.     MD2020. MD2030. MD2040: Check and adjust if
 20. MD2O10, MD2020: Fit the alternator and clamp. Fit               necessary the valve clearance for cylinder No. 1,
     the drive belt.                                                 and the clearance for the outlet valve on cylinder
                                                                     No. 2.
     Note: I t should be possible to press in the belt ap-
     prox. 10 mm (.40 in) between the pulleys.                      Pull round the crankshaft 240 (2/3 turn) anti-clock-
                                                                    wise (seen from front) and adjust the clearance for
 21. Connect the hose to the sea water pump and tigh-
                                                                    cylinder No. 3 and the clearance for the inlet valve
     ten'the clip. Connect the exhaust pipe.                        on cylinder No. 2.
22. Fill with refrigerant. See "Replenishment of refrige-
     ra t on page 64.
23. Connect the battery cables. Open the fuel cocks
    and bottom valve. Start the engine and check that        5.     Clean the valve cover and fit it. Replace the seal if
    no leakage occurs.                                              damaged. Test run the engine and check that no
                                                                    l eakage occurs.

Adjusting the valves
Note! The clearance must never be checked when
the engine is running.
Valve clearance (cold engine):
I nlet and outlet for all engines: 0.20 mm (.0078 in).       Dismantling of piston, piston rings and
1.   Dismantle the valve cover.                              connecting rod
2.   Turn the engine in its normal direction of rotation     1.     Empty the cooling system and drain or syphon out
     until both valves for cylinder No. 1 are closed (com-          the engine oil.
     pression position). Continue turning the engine         2.     Dismantle the cylinder head. See "Dismantling of
     round until the marking of flywheel shows 0 0.                 cylinder head" on page 25 and 26.

                                                                   Fig. 38. Dismantling of oil strainer with induction
              Fig. 37. Adjusting the valves
3.   MD2O10: Check and adjust if necessary the valve         3.     Remove the sump and plate` over the sump.
     clearance for cylinder No. 1.                                  Remove the oil pump's induction manifold.
     Pull round the crankshaft 180 (1/2 turn) clockwise             There is no plate on the MD2O10-40C.
     (see from front) and adjust the clearance for cylin-
     der No. 2.

                                                                                                            Engine body

4.   Turn round the crankshaft until the piston in ques-       I nspection and matching of piston rings
     tion is in the lower turning position. Dismantle the
     main bearing cap with lower bearing cup.                  Check the wear surfaces and sides. Black patches on
                                                               the surfaces imply poor contact and indicate that it is
                                                               ti me to change the piston rings. The oil consumption is
                                                               also a critical factor as to when a piston ring should be
                                                               Check the piston ring gap (Fig. 41). Push down the ring
                                                               below the lower turning position by means of a pis-
                                                               ton. Replace the piston ring if the gap exceeds 1.0 mm
                                                               (.039 in).

              Fig. 39. Dismantling of piston

5.   Place a pair of plastic hoses as protection over the
     connecting rod screws. Carefully tap up the con-
     necting rod with piston far enough so that the pis-
     ton rings are released from the cylinder bore. Lift off
     the piston together with the connecting rod.
     Note: Scrape off the soot strip in the top part of the
     cylinder bore to simplify dismantling.

6.   Dismantle piston ring with a piston ring tongs.

                                                                         Fig. 41. Checking of piston ring gap

                                                               Piston rings should also be replaced if there is noticea-
                                                               ble wear or out-of-roundness in the cylinders since the
                                                               rings seldom have the same position as they had before
                                                               Check the piston ring gap also on new rings.
                                                               See "Technical data" for size info.
                                                               Check the clearance in the piston ring groove. Roll the
                                                               ring in its groove in the piston and measure the clear-
                                                               ance at a number of points with a feeler gauge.

           Fig. 40. Dismantling of gudgeon pin

7.   Remove the circlips for the gudgeon pin and dis-
     mantle the gudgeon pin carefully with a suitable

 Engine body

Assembly of piston, piston rings
and connecting rod                                         6.    Check the big-end clearance. See "Inspection of
                                                                 crankshaft" and "Inspection of main and big-end
Note: Check that pistons of the correct oversize are             bearings" on pages 46 and 47.
used if the cylinders have been milled to oversize.
                                                           7.    Check the piston ring gap in the cylinder bore (Fig.
1.    Fit one circlip in the piston.                             41 on page 35) and that the rings do not jam in the
2.   Oil in the gudgeon pin and bushing.                         piston ring grooves.

     Fig. 49. Assembly of piston and connecting rod
                  ( MD2010, MD2020)

                                                                        Fig. 51. Placement of piston rings
                                                                1. TOP marking
                                                                2. Oil scraper with expander spring (MD2O10-2030)

     Fig. 50. Assembly of piston and connecting rod
                  ( MD2030, MD2040)

3.   Heat up the piston to approx. 100C (212F). Place
     the piston and connecting rod so that the markings
     correspond with Fig. 49 or 50.
     MD2O10, MD2020: With the marking on the con-
     necting rod's side upwards the arrow on the piston
     top should be turned in the same direction as per
     Fig. 49.                                                          Fig. 52. Fitting of oil ring (MD2040)
     MD2030, MD2040: The marking on the connecting                    1. Top scraper ring   3. Bottom scraper ring
     rod and the "SHIBAURA" mark in the piston should                 2. Expander
     be turned in the same direction as per Fig. 50.

     Push in the gudgeon pin.                             8.    Fit the piston rings on the piston with a piston ring
     NOTE! The gudgeon pin should be able to be                 tong.
     pressed in easily. It must not be knocked in.              Note: The rings should be turned as per Fig. 51.
                                                                MD2O10, MD2020, MD2030 : Fit the oil ring first
4.   Fit the other circlip.                                     (with the marking turned upwards). The opening in
                                                                the expander spring should be placed 180 from the
5.   Check that the connecting rod goes easily in the           oil ring gap.
     gudgeon pin bearing.

                                                                                                             Engine body

     MD2040: Place the expander (2, Fig. 52 on page
     38) to the oil scraper rings in the piston ring groove.
     Check that the ends on the expander do not over-
     l ap each other. Fit the top scraper ring (1) over the
     the expander. Put in one end of the ring in the
     groove and hold it in place with your thumb. Push
     the ring in position with your other thumb.
     Fit the lower scraper ring (3) in the same way.
                                                               Fig. 53. Number marking on connecting rod and cap

     Check that the scraper rings run easily in both di-
     rections and that the ends on the expander and the
                                                               3.   Check that the marking on the piston top, alt. in the
     rings are in the correct position (Fig. 52).
                                                                    piston and on the connecting rod, correspond with
                                                                    Fig. 53.
                                                                    Use a piston ring compressor and fit the piston with
                                                                    connecting rod in the respective cylinder, beginning
                                                                    with cylinder No. 1 (first).
                                                                    Note: The connecting rod with the l owest number
                                                                    should be fitted first (to cylinder No. 1) and subse-
                                                                    quently the connecting rod with the highest number
                                                                    closest to the flywheel.
                                                                     The connecting rod should be turned with the mark-
                                                                     i ng (number/colour marking) turned "towards the in-
                                                                    j ection pump" (camshaft side). The arrow on the
                                                                     piston top alt. at the gudgeon pin hole should there-
                                                                     by point forwards.

Fitting of piston in cylinder
Note: After replacing a connecting rod, piston or gudg-
eon pin the weight difference between the connecting
                                                               4.   Fit the bearing cap and tighten the connecting rod
rod complete with piston and piston rings must not ex-
                                                                    screws. See "Technical data" for tightening torque.
ceed 10 g (0.35 oz) between the different cylinders.
                                                                    Note: The main bearing cap should be fitted so that
                                                                    the number/colour marking on the crankshaft and
                                                                    cap correspond (Fig. 53).
1.   Lubricate the piston and piston rings with engine oil          Undamaged connecting rod screws do not need to
     and turn the rings so that the oil penetrates the pis-         be changed and can be re-fitted.
     ton ring groove. Turn the piston rings so that the
     piston ring gaps are divided by 900 from each other.
     Note: Make sure that no piston ring gap is posi-
     tioned opposite the piston bolt or at right angles to
     i t.
     MD2040: Check that the ends on the expander and
     scraper rings are in the correct position (Fig. 52).
2.   Place the bearing cups in their positions in the con-
     necting rod and cap. Check that the hole in the
     bearing cups comes opposite the hole in the con-
     necting rod. Oil in the crank pin with engine oil.

 Engine body

 Timing gears                                                 Dismantling of the timing gear
 Replacement of front crankshaft seal                         Q      WARNING! If the crankshaft and camshaft are
                                                                     turned without being synchronised with each
                                                                     other the valves can go against the pistons and
The seal consists of a rubber ring and can be replaced               be damaged.
after the crankshaft pulley has been removed. Use a
universal extractor.                                          1.   Close the fuel cocks. Remove both battery leads.

 1.   Tap in one side of the seal so that it goes on edge.
      Pull out the seal with a hook.                         2.    Close the bottom valve. Release the rubber hoses
                                                                   to the sea water pump and drain out the water in
                                                                   the sea water system.

                                                             3.    Remove the sea water pump.

                                                             4.    Remove the drive belt for the alternator.

              Fig. 54. Fitting of crankshaft seal

3.    Oil in the new seal with fit it with a suitable man-

                                                                       Fig. 56. Dismantling of crankshaft pulley

                                                             5.    Remove the pulley from the crankshaft. Use a uni-
                                                                   versal extractor (Use an adjustable spanner on the
                                                                   l ug on the pulley as a counterhold when the nut is

            Fig. 55. Fitting of crankshaft pulley            6.    Remove the delivery pipe complete. Release the
4.    Remove the fitting tool. Fit the key and crankshaft          fuel house and fuel leak pipe at the injection pump.
      See Technical data for tightening torque.

                                                                                                             Engine body

                                                                Fig. 59. Dismantling of circlip to cover for the oil pump

         Fig. 57. Dismantling of injection pump                10. Remove the circlip for the intermediate gear
               1. Lock pin          2. Shims                       ( Fig. 59). Take care of the sleeve washer, spring
                                                                   and shims.
                                                                   Lift off the gear complete with cover and oil pump.
7.   Release the injection pump. Turn the stop lever
     clockwise and carefully lift up the pump so that the
     l ock pin to the regulator arm is accessible (Fig. 57).   11. Dismantle the crankshaft gear with a universal ex-
     Remove the lock pin and release the regulator arm.
     Lift off the injection pump.                              12. If the camshaft gear is to be dismantled the cam-
                                                                   shaft must be removed complete. See under head-
     NOTE! Take care off the shims under the injec-                 ing "Dismantling of camshaft" on page 44.
     tion pump flange.

                                                               I nspection of timing gears
8.   Dismantle the timing gear casing.

                                                                      Fig. 60. Checking of gear flank clearance

                      2                                        Clean the gears and other parts of the timing gears and
                                                               check them carefully. Replace gears which are heavily
           Fig. 58. Timing gears, basic setting                worn or damaged.
          1. Crankshaftgear      3. Camshaftgear               Check the flank clearance with a feeler gauge or a dial
          2. Intermediate gear                                 gauge.
                                                               Max. permissible flank clearance: 0.25 mm (.0098 in).
                                                               Note: If the flank clearance exceeds the permissible
9.   Pull round the engine until the markings on the tim-
                                                               value all the the gears in the timing gears should be re-
     i ng gears correspond.

 Engine body

Fitting and adjustment

       WARNING! I f the crankshaft and camshaft are
Q      turned without being synchronised with each
       other the valves can go against the pistons and
       be damaged.
Note: The gears in the timing gears which are of import-
ance for adjustment are marked as follows:
Crankshaft gear - the intermediate gear is marked with
a punch mark and the intermediate gear - camshaft
gear with a circle opposite the tooth and tooth gap                Fig. 62. Intermediate gear complete with oil pump
(Fig. 61).                                                                Circlip              7. Spring
                                                                          Spring washer        8. I ntermediate gear
1.   Put the key in position in the crankshaft and fit the                Spring
                                                                                                  complete with outer
     crankshaft gear.                                                     Shims                   rotor

                                                                       5. Cover to oil pump
2.   Fit the camshaft complete with regulator weights.                                         9. Thrust washer
     Carry out work steps to item 4 under the heading                  6. I nner rotor
     "Fitting of camshaft" on page 45.

                                                              4.    Grease in the oil pump's inner rotor (6, Fig 62) and
                                                                    housing (outer rotor, 8).
                                                                   Fit the inner rotor and cover to the oil pump. Fit the
                                                                   shims, spring, spring washer and lock washer as
                                                                   per Fig. 62.


           Fig. 61. Timing gears, basic setting
           1. Crankshaft gear      3. Camshaft gear
           2. I ntermediate gear

                                                                    Fig. 63. Checking of oil pump's axial clearance

                                                              5.   Adjust the oil pump's axial clearance to 0.10-0.15
                                                                   mm (.0039-.0059 in). Shims are available in sizes
                                                                   0.10; 0.15; 0.20 and 0.50 mm (.0039, .0059, .0078
                                                                   and.0196 in)
3.   Fit the thrust washer (9, Fig. 62) on the intermedi-
     ate gear's shaft journal. Fit the intermediate gear as
     per the markings (Fig. 61).                              6.   Check the crankshaft seal in the timing gear cas-
                                                                   i ng, and replace if necessary. See under heading
     NOTE! Do not turn the crankshaft before the
     ti ming gear casing is fitted.                                "Replacement of front crankshaft seal" on page 40.

                                                                                                            Engine body

                                                                   NOTE! Make sure that the shims which were
                                                                   placed under the injection pump flange are re-
                                                                   placed in position before the pump is placed in the
                                                                   cylinder block (applicable where the pumps has
                                                                   been removed).

                                                              10. Tighten the timing gear casing and injection pump.
                                                                   Tightening torque: see Technical data.

                                                              11   Check the injection start (crankshaft position) in the
           Fig. 64. Fitting of timing gear casing                  event that a new injection pump or complete new
                                                                   camshaft is fitted and if a new cylinder block is
7.                                                                 used.
     Centre the cover in front of the oil pump.
      Note: The hole in the cover should be in the posi-            Se directions under the heading "Adjustment of in-
     tion shown in Fig. 64 (which it should if the mark-           j ection angle" on pages 55 and 56.
     i ngs on the gear wheel coincide according to Fig.
     61).                                                     12. Connect the fuel hose to the injection pump.
                                                                   Fit the delivery pipe.
8.   Place the timing gear casing in position with a new           Tightening torque: see Technical data.
     gasket. Observe care so that the crankshaft seal is
     not damaged.
     Check that the start spring is in position in the tim-
     i ng gear casing and is connected to the regulator
     arm (link arm).
     Put in the regulator through the hole in the cylinder
     Note: Check that the tubular pip in the timing gear
     casing can engage in the hole in the oil pump
     cover. Turn the cover backwards and forwards and
     centre it in mid position.

                                                                         Fig. 66. Fitting of crankshaft pulley

                                                              13. Put the key in position in the crankshaft and fit the
                                                                  crankshaft pulley.
                                                                   Tightening torque: see Technical data.

             Fig. 65. Fitting of injector pump
              1. Lock pin           2. Shims

9.   Turn the stop lever clockwise and connect the arm
     to the injection pump. Fit the lock pin.

' Engine body

14. Fit the sea water pump on the timing gear casing.        6.        MD2O10, MD2020: Remove the gear for the
    Connect the water hoses to the pump.                               mechanical tachometer drive*.
15. Fit the drive belt to the alternator.                    * Note: Mechanical tachometer driving is not used by Volvo
                                                               Penta. The gear must, however, be in position.
     Note: If the tension is correct the belt should be
     able to be pressed in approx. 10 mm (.40 in) be-
     tween the pulleys.
16. Open the fuel cocks. Bleed the fuel system as per
    the directions on page 59.                               Inspection of valve lifter and camshaft
17. Connect the battery leads.
                                                             NOTE! If the lifter is worn over the lift surface the lifter
                                                             must be scrapped. The "dike" shows that the lifter has
                                                             not rotated. A dark stripe on the outer lift surface shows,
                                                             however, that the surface is not worn.
                                                             It is the condition of the valve lifters that determines
                                                             whether further checking of camshaft wear is
Camshaft                                                     necessary.

Dismantling the camshaft                                     The cam for example may be skew worn in an axial di-
                                                             rection. This can in less severe cases be adjusted by
1.   Dismantle the cylinder head. See "Dismantling of        grinding the cams. Replace the camshaft in the event of
     cylinder head" on page 25. Lift out the valve lifters   further damage or wear.
     and place them in order in a rack.
                                                             Note: When replacing the camshaft all the valve lifters
2.   Remove the timing gear casing. See under heading        must be replaced.
     "Dismantling of timing gear" on pages 40 and 41.
3.   Remove the regulator sleeve from the camshaft.

                                                             Measuring the camshaft



                                                                            Fig. 68. Measuring the camshaft.
            Fig. 67. Dismantling of camshaft
          1. Gear               3. Regulatorsleeve           Cam height (inlet and outlet) "A", Fig. 68.
          2. Lock washer                                      MD2O10, MD2020, MD2030:                    min. 26.1 mm
                                                                                                             (1.027 in)
4.   Remove the screws for the lock plate (one screw is       MD2040:                               33.7 mm (1.326 in)
     accessible through the hole in the camshaft gear),      Cam height "B" (for injection pump)
     Fig. 67.                                                 MD2O10, MD2020:                 min. 34.3 mm (1.350 in)
5.   Lift out the camshaft complete with gear and regu-       MD2030:                              33.8 mm (1.330 in)
     l ator weights.                                          MD2040:                              41.8 mm (1.645 in)

     Note: Observe care so that bearings, bearing races      Cam height "C" (for feed pump)
     or cams are not damaged.                                 MD2O10, MD2020, MD2030:                     min. 27.0 mm
                                                                                                              (1.062 in)
     On MD2030 and MD2040 the gear for the mechan-             MD2040:                               30.0 mm (1.181 in)
     i cal tachometer drive* must be removed together
     with the camshaft.                                      Replace the camshaft if the wear tolerances are not

                                                                                                             Engine body

Fitting the camshaft                                            4. Fit the regulator sleeve (3). Note: The sleeve
                                                                   should engage with the pin on the camshaft gear.
Note: If parts have been replaced on the camshaft the
fitting of these should take place in the order shown in           * Note: Mechanical tachometers are not used by .
Fig. 69.                                                           Volvo Penta, but the gear must still be put in

                                                                5. Check that the markings on the timing gear corre-
                                                                   spond (Fig. 58 on page 41).

                                                                6. Carry out the work as per items 8 to 11 under the
                                                                   heading "Fitting and adjustment (timing gears) on
                                 V1                                page 43.

     410                                                        7. Lubricate the mating surface on the valve lifters to
                                                                   the camshaft with molybdenum disulphide and oil in
                                                                   the guides in the cylinder block. Fit the valve lifters
                       Fig. 69. Camshaft                           i n the correct order.
       1. Camshaft              5. Gear for drive of
       2. Key                      mech. tachometer*
                                                                8. Fit the pull rods and rocker mechanism. Tightening
       3. Roller bearing        6. Camshaft gear
       4. Spacer rings          7. Regulator sleeve                torque, see Technical data.

       * Note: Mechanical tachometers are not used by Volvo
         Penta, but the gear must still be put in position.     9. Carry out the work as per items 6 to 8 under the
                                                                   heading "Fitting of cylinder head" on page 32.

                                                               10. Adjust the valve clearance as per the direction of
                                                                   page 34. Fit the valve cover.
                                                                   Tightening torque, see Technical data.

                                                               11. Carry out the work as per items 12 to 17 under the
                                                                   heading "Fitting and adjustment (timing gears) on
                                                                   pages 43 and 44.

                 Fig. 70. Fitting the camshaft
            1. Gear               3. Regulatorsleeve
            2. Lock washer

1.    MD2O10, MD2020: Fit the gear (1, Fig. 70) for the
      mechanical tachometer drive*.
2.    Oil in the camshaft's bearing races and carefully lift
      the camshaft in position complete with gear and
      regulator weights (together with the gear (1) for the
      mechanical tachometer drive* on MD2030 and
      M D2040.
      Note: Observe care so that bearings, bearing races
      or cams are not damaged.
3.    Fit the lock washer (2) for the camshaft in the cor-
      rect position and tighten it. Tightening torque:
      9-13 Nm (6.6-9.6 ft.lbs).

 Engine body

Crank mechanism                                                Inspection of crankshaft
 Dismantling of crankshaft                                     Clean the crankshaft carefully in all channels after dis-
                                                               mantling and inspect it very carefully to confirm whether
(engine removed)                                               it really need renovating.
 1.   Dismantle the reverse gear alt. S-drive and adapter
      plate and coupling, flywheel and flywheel housing.
2.    Remove the cylinder head. See under heading
      "Dismantling of the cylinder head" on pages 25
      and 26.
3.    Remove the valve lifters and place them in order in
      a rack.                                                             1   2     1   2
4.    Remove the pistons with connecting rods. Carry
      out the work steps to item 5 under the heading
      "Dismantling of piston, piston rings and connecting                                   Qum
      rod" on pages 34 and 35.
5.    Remove the timing gear casing. Carry out the work
      steps to item 8 and item 10 under the heading "Dis-
      mantling of timing gears" on pages 40 and 41.

                                                                     Fig. 72. Check measurement of crankshaft

                                                              1.   Check the wear and out-of-roundness with a mi-
                                                                   crometer. Measure the diameters "A-A" and "B-B"
                                                                   i n items "1" and "2" (See Fig. 72).
                                                                   The max. permissible conicity and out-of-roundness
                                                                   on the main and big-end bearings is 0.05 mm
                                                                   (.0019 in). Grind the crankshaft to an appropriate
                                                                   undersize if these values are exceeded. Bearing
                                                                   cups are available in two oversizes.
                                                              2.   Measure the crankshafts longitudinal curvature
                                                                   (distortion). Place the crankshaft on a pair of V-
                                                                   blocks placed under the front and rear of the main
                                                                   bearing journal. Alternatively the shaft can be
         Fig. 71. Dismantling of main bearing cap                  braced between spikes. Measuring should be car-
                                                                   ried out on the middle main bearing journal(s).
                                                                   Max. longitudinal curvature (distortion): 0.06 mm
                                                                   (.0023 in).
6.    Remove the lock screws which hold the main bear-             If this value is exceeded the crankshaft must be
      i ng cap (Fig. 71). Carefully lift off the crankshaft        aligned or replaced.
      complete with cap backwards.
                                                              3.   Check that the mating surfaces on crankshaft seals
       Note: Tape the crankshaft gear to protect the bear-         are not worn or damaged.
      i ng surfaces in the block during dismantling.

7.    Remove the main bearing cap from the crankshaft.
      MD2040: Take care of both thrust washers in the
      rear cap.

                                                                                                           Engine body

Grinding of the crankshaft
To achieve satisfactory results in connection with grind-      I nspection of front crankshaft bushing
ing the following factors should be taken into considera-      Check the bearing clearance between the big-end jour-
tion:                                                          nal and bushing. Use a cylinder indicator and a micro-
1.   Grind the crankshaft in a crankshaft grinding ma-         meter.
     chine to the undersize as per "Technical data". Sur-
     face fineness 1.6 Z ( VVV) for bearing races
     (B, Fig. 73) and recess radius are achieved by rub-
     bing with emery cloth No. 400.

                                                                        Fig. 74. Checking of bearing clearance

                                                               1.   Measure the bushing's inner diameter at points 1
                                                                    and 2 as per Fig. 72 on page 46. Measure in two
                                                                    directions ("A" and "B") at each point.

              Fig. 73. Checking of recess radius
                                                               2.    Measure the bearing journal's outer diameter and
                                                                     calculate the bearing clearance (difference be-
2.   It is very important that the recess radius is the cor-         tween the previous measurement and the bearing
     rect size.                                                     j ournal's max. diameter).
     Recess radius:                                                 Max. bearing clearance: 0.2 mm (.0078 in).
     - At main and big-end bearing journals,
        "A" = 3  0.25 mm (.1181 .0098 in)                    Replace the bushing if the clearance exceeds the per-
     - At oil holes, "C" = min. 2 mm (.0787 in),               missible value. Where necessary the crankshaft can be
        max. 5 mm (.1968 in).                                  ground to an appropriate undersize and the bushing
     Grinding hacks and sharp edges must be avoided            can be replaced with a corresponding oversize.
     since these can give rise to crankshaft fracture.         Note: Check the bearing clearance again before the
3.   Clean the crankshaft well from grinding residue and       crankshaft is fitted if it has been re-ground.
     other impurities. Flush and clean the oil channels.

I nspection of main and big-end bearings
Check the main and big-end bearing cups and the front
crankshaft busing. Replace worn bearings or those with
damaged bearing surfaces.

 Engine body

Replacement of front crankshaft bushing                       5.   Check that the oil channel is open after pressing in.
1.   Dismantle the bushing from the cylinder block.                Check also the bushing's inner diameter. See
                                                                   "Technical data" for size.
2.   Check that the bushing's mating surface in the
     block has no burrs or upset ends.

                                                              Checking of big-end bearing clearance
                                                              Special tool: 856927-9 (measuring plastic)
                                                              The big-end bearing's radial bearing clearance can be
                                                              checked by means of the measuring plastic (part. No.
                                                              856927-9) as follows:

              Fig. 75. Marking up of oil hole

3.   Draw a line over the hole in the block and bushing
     with a marker pen (Fig. 75). Oil in the outside of the
     bushing and its mating surface in the block.

                     I'-                                      1.
                                                                      Fig. 77. Application of measuring plastic

                                                                   Wipe clean the big-end bearing and big-end journal
                                                                   from oil. Cut a piece of measuring plastic to the
                                                                   same length as the bearing width and apply the
                                                                   measuring plastic along the big-end journal
                                                                   (Fig. 77).
                                                                   Note: Avoid the oil hole.

              Fig. 76. Fitting of the bushing                 2.   Fit the connecting rod and cap (note markings cor-
                                                                   respond) and tighten the crankshaft screws.

4.                                                                 Tightening torque, see Technical data.
     Make sure that the bushing's oil hole corresponds
     with the oil channel in the cylinder block and press
     i n the new bushing to the correct depth.                     NOTE! Do not turn the connecting rod or crank-
     NOTE! The bushing should be pressed in from the               shaft since this will destroy the measuring strip.
     front of the block and with the bevelled side of the
     bushing turned forwards (Fig. 76).

                                                                                                              Engine body



      Fig. 78. Check measuring of measuring plastic

3.   Remove the cap and measure the width on the
     pressed out measuring plastic at the widest point.             Fig. 79a. Fitting of main bearing cap MD2O10,
     Use the scale which accompanies the measuring                                  MD2020, MD2030
     plastic (Fig. 78).                                           1. Big-end bearing cap with 4. Main bearing cap of
                                                                     bevelling                     cast iron
     Max. permissible big-end bearing clearance:                  2. Groove                     5. Main bearing cap of
     0.2 mm (.0078 in).                                           3. Top main bearing half         aluminium
     Replace the big-end bearing if the bearing clear-               with oil groove
     ance exceeds the permissible value. If necessary
     the journals can be ground to an undersize and
     oversize bearings fitted. Big-end bearings are avail-
     able in two oversizes.
     NOTE! Check the bearing clearance again before
     assembly if the journals have been ground.

Fitting of the crankshaft
1.   Check the cleaning of the crankshaft channels and
     bearing surfaces, cylinder block and cap. Check
     also that the bearing cups and their mating surfac-     4
     es have no burrs or upset ends.
2.   Place the main bearing in position in the cap.                Fig. 79b. Fitting of main bearing cap MD2040
     Check that the lubrication holes in the top bear-
                                                                  1. Big-end bearing cap with   3. Top main bearing half
     i ng cups come opposite the oil channels.
                                                                     bevelling                     with oil groove
3.   Oil in the bearing and main bearing journals and fit         2. Groove                     4. Thrust washers
     the caps on the crankshaft.
     Note : The bevelled edge (1, Fig. 79a and 79b)
     should be turned forwards on all caps.
                                                             5.   Carefully lift the crankshaft in position in the cylin-
4.   Fit the cap which is provided with a groove as per
                                                                  der block.
     2, Fig. 79a and 79b.
                                                                  Note: Tape the crankshaft gear before the crank-
     Note: The bearing cups provided with an oil groove           shaft is lifted in. The cogs can otherwise damage
     (3, Fig. 79a and 79b) should be placed in the top
                                                                  the bearing surfaces in the cylinder block.
     MD2O10, MD2020, MD2030: Fit aluminium caps
     (with integrated thrust washers) at the far end (fly-
     wheel side).
     MD2040: Place both thrust washers in the lower
     cap at the far end (flywheel side) and with the oil
     groove turned towards the crankshaft.

Engine body

6.   Tighten the main bearing cap. Tightening torque,           Replacement of rear crankshaft seal
     see Technical data.                                        The seal consists of a rubber ring and becomes access-
                                                                i ble after the adapter plate at the back of the flywheel
                                                                housing, the flexible coupling, flywheel* and flywheel
                                                                housing have been removed.
                                                                *Note: Mark up the position of the flywheel in relation to
                                                                the crankshaft (simplified fitting).

                                                                1.   Clean the position for the sealing ring in the cylinder
                                                                     block and the mating surface on the flywheel hous-

            Fig. 80. Checking of axial clearance

7.   Check that the axial clearance does not exceed
     0.5 mm (.0196 in).

Replacement of gear ring on the flywheel
1.   Mark up the position of the flywheel in relation to
     the crankshaft (to simplify fitting). Dismantle the fly-

2.   Drill one or a couple of holes in a tooth gap on the                   Fig. 81. Fitting of crankshaft seal
     gear ring. Split the ring at the drilled hole with a
     chisel, after which the gear ring can be removed.

                                                                2.   Apply an even layer of sealing compound (VP no.
3.   Brush clean the mating surface on the flywheel with             840 879) round the flywheel housing's mating sur-
     a steel brush.                                                  face (screw holes).
                                                                     Apply grease on the sealing lip and fit the seal.

4.   Heat up the new gear ring in an oven (120-150C/
     248-302F) so that the gear ring becomes evenly            3.    Fit the flywheel housing, flywheel, the flexible coup-
     hot all round.                                                  li ng, and the adapter plate.
                                                                     Tightening torque, see Technical data.
5.   Place the heated gear ring on the flywheel and
     drive on with a hammer and soft mandrel. The gear
     ring should then cool in the free air.

6.   Clean the mating surfaces on the flywheel and
     crankshaft. Check the rear crankshaft seal. Re-
     place if necessary.

7.   Fit the flywheel in the correct position (guide pin on
     MD2030 and MD2040).
     Tightening torque, see Technical data.

                                       Lubricating system

General                                                          Oil filter
The engines are provided with a pressure lubricating             The oil filter is of the full flow type which implies that all
system with an oil filter of the full flow type.                 the oil is filtered before it is pressed out to the bearing
                                                                 The filter is placed on the right-hand side of the cylinder
Oil pump                                                         block. The filter element consists of folded filter paper.

The oil pump is placed in the intermediate gear in the           I n the bottom of the filter there is an overflow valve
transmission, and from where it is also driven.                  (A, Fig. 82) which opens and releases oil past the filter
                                                                 if the insert should be blocked.
The pump is of the rotor type with an inner and outer ro-
tor placed eccentrically in relation to each other. The in-      The filter is of the disposable type and is scrapped after
ner rotor has one "cog" less that the outer rotor.               use.

The function of the pump is based on the increase and
decrease of the space between the outer and inner ro-
tor cogs. During the first part of the inner rotor's rotation
speed the volume is increased, whereby an underpres-
sure occurs and oil is induced in through the inlet. After
approx. 1/2 turn the space is reduced and a pressure
condition occurs which presses out oil through the

Reducing valve
The oil pressure is limited by a reducing valve. The
valve is placed in the lubricating system just in front of
the oil filter and is fitted on the right-hand side of the cy-
li nder block in front of the oil filter.                                          Fig. 82. Oil filter
The valve opens at excessive high pressure and releas-                             A. Overflow valve
es oil back to the sump.

Crankcase ventilation
To prevent overpressure and to separate fuel vapour,
steam and other gaseous combustion products, the en-
gine is fitted with enclosed crankcase ventilation.

Lubrication system

Repair instructions
Checking of the oil pressure
The oil pressure can be checked by connecting a ma-
nometer with hose to the connection for the oil pressure
contact (thread size in cylinder head = 1/8"). The oil
pressure should at running speed and temperature be
150-500 kPa (1.5-5 kp/cm 2 , 21.3-71.1 lbf/in 2).
If the oil pressure is too high or too low the reducing
valve can be replaced first and then the oil pressure
checked again.
The valve is fitted on the right-hand side of the cylinder
block in front of the oil filter (Fig. 83).                           Fig. 84. Checking of oil pump clearance
                                                                        1. Inner rotor       2. Outer rotor
                                                                        A. Max 0.25 mm (.0098 in)

                                                             Fitting of the oil pump
                                                             When fitting the oil pump follow the items 4-10 and
                                                             12-17 under the heading "Fitting and adjustment"
                                                             (transmission) on pages 42-44.

                                                             Replacing the oil filter

                                                             A      WARNING! Hot oil can result in burn injuries.

                                                             1.   Place a collection vessel under the oil filter.
                                                             2.   Unscrew the oil filter and discard (watch out for oil
                                                                  spillage). Use a filter extractor.
         Fig. 83. Replacement of reducing valve
                                                             3.   Moisten the new filter's rubber gasket with oil and
                                                                  check its mating surface on the bracket.

Oil pump
                                                             4.   Screw on the new filter by hand until the gasket
                                                                  makes contact with the sealing surface, and then
Dismantling of the oil pump                                       tighten the filter an additional 1/2 turn.
                                                             5.   Replenish if necessary the oil in the engine and
1.   See under the heading "Dismantling of the timing
                                                                  start it. Check that no leakage occurs.
     gears" on pages 40 and 41. Carry out the work
     steps 1 to 9.
2.   Remove the circlip for the intermediate gear. Take
     care of the circlip, sleeve washer, spring. shims
     and oil pump cover.
                                                             Oil channels
                                                             Clean up and flush the oil channels in the engine with
                                                             cleaning liquid and then with steam or flushing oil at a
                                                             pressure of 300-400 kPa (3-4 kp/cm 2 , 42.6-56.8 lbf/int)
I nspection of the oil pump                                  i n connection with more extensive engine overhaul.
                                                             Note: Do not forget to clean the oil pressure pipe be-
1.   Check that the oil pump cover and the inner and
                                                             tween the cylinder block and cylinder head.
     outer rotor are not worn or damaged.
                                                             Clean the drilled oil channels in the cylinder block,
2.   Check the clearance between the outer and inner
                                                             crankshaft and in the connecting rods with a cleaning
     rotor (Fig. 84). Max. permissible clearance
     0.25 mm (.0098 in).                                     brush.

Note. Contact Volvo Penta service department if the
shaft journal for the intermediate gear and oil pump
needs to be replaced.

                                                  Fuel system

General                                                       Injectors
The fuel is induced by the feed pump from the fuel tank        The engines are fitted with injectors (Fig. 86). Each in-
through a water separating pre-filter (accessory) and         j ector basically consists of a nozzle holder and a
pressed through the fine filter to the injection pump          nozzle.
(Fig. 85).
                                                              When the fuel pressure has increased to the set value
Return fuel from the injectors is led through the fuel leak   (opening pressure) the nozzle needle (pin) (5) lifts
pipe/return pipe back to the tank.                            which is held pressed against its seat by the thrust
                                                              washer (6) and atomised fuel is injected into the en-
                                                              gine's precombustion chamber.
                                                              The injector's opening pressure is determined by the
                                       3                      tension of the thrust washer, which in turn is adjusted
                                                              with adjuster washers (7).


         Fig. 85. Fuel system, principle drawing
           1. Fuel tank          4. Fine fuel filter
           2. Pre-filter         5. Injection pump
           3. Feed pump          6. Injector

I njection pump
The injection pump is a flange-mounted in-line pump
placed on the right-hand side of the engine. The pump
i s driven via cams on the engine's camshaft which di-
rectly activate the pump element.
                                                                               Fig. 86. Injector, complete
                                                                      1.   Packing                6.   Thrust washer
                                                                      2.   Nozzle nut             7.   Adjusterwashers
Centrifugal regulator                                                 3.   Nozzle sleeve          8.   Nozzle holder
                                                                      4.   Spacer                 9.   Nut
The regulator is mechanical and works with speed                      5.   Nozzle needle (pin)
sensing regulator weights. It is fitted at the front on the
camshaft gear from where it is also driven.
The regulator weights activate the injection pump's con-
trol rod via the regulator sleeve, a lever and a regulator
arm. The speed is regulated over the entire engine
speed range, from low idling speed to high speed (uni-
versal type).
                                                              Fuel filter
                                                              The fuel filter is of the disposable type. The filter insert
Feed pump                                                     consists of a specially wound paper filter.

The feed pump is also positioned on the right-hand of
the engine and is driven via a cam on the engine's cam-

Fuel system

Repair instructions                                        4.   Send the pump to an authorised diesel workshop*
                                                                for inspection if the workshop does not have spe-
Observe the greatest possible cleanliness when work-            cially trained personnel with the necessary testing
i ng with the fuel system.                                      equipment.
                                                           'MD2o10, MD2020, MD2030: Nippondenso.
                                                            MD2040: Bosch.
Injection pump
Dismantling of the injection pump
NOTE! Repair work on the injection pump which
may change its setting should only be carried out
by specially trained mechanics which have the
requisite equipment at their disposal.
Engine warranties are not longer valid if the seals
are broken by unauthorised personnel.
1.   Carefully wash clean the injection pump, pipes and    Fitting of the injection pump
     the engine around the pump.                           Check that the pump is in good condition, and if so re-
2.   Close the fuel cocks. Remove the delivery pipe        quired also tested and approved before it is fitted.
     complete. Release the fuel hose from the pump.        Note: Do not remove the protective caps before the
     Fit protective caps on all connections.               pipes are connected.

                                                           1.   Put the injection pump in the cylinder block.
                                                                NOTE! Make sure that the shims which were
                                                                placed under the injection pump flange are put
                                                                back in place before the pump is'put in the
                                                                Note: The correct pump setting is normally ob-
                                                                tained with this method. If the injection pump, cam-
                                                                shaft or cylinder block have been replaced the set-
                                                                ting of the pump must be adjusted. See next
                                                                section, "Adjustment of injection angle":
                                                           2.   Turn the stop lever clockwise and connect the
                                                                regulator arm to the control rod on the pump. Fit the
                                                                l ock pin (Fig. 87). Screw tight the pump.
                                                           3.   Connect the fuel hose and fuel leak pipe to the
                                                                pump. Fit the delivery pipe.
                                                           4.   Bleed the fuel system and test run the engine.

        Fig. 87. Dismantling of the injection pump
              1. Lock pin         2. Shims

3.   Dismantle the pump's attachment screws and nuts.
     Turn the stop lever clockwise and carefully lift up
     the pump so that the lock pin to the regulator arm
     becomes accessible (Fig. 87).
     Remove the lock pin and release the regulator arm.
     NOTE! Take care of the shims under the injec-
     tion pump flange when the pump is lifted off the
     cylinder block.

                                                                                                                 Fuel system

Adjustment of injection angle                                       Use a scrapped fuel pipe. The pipe makes it easier
                                                                    to see when the fuel begins and stops flowing out
Fit the injection pump as per the previous section with             from the valve.
the exception of item 1 which is changed to item 1 be-

1.   Place a shim 0.5 mm (.0196 in) in thickness under
     the injection pump flange.

                                                                     Fig. 90. Marking the pulley and engine block
                  Fig. 88. Fitting of shim
                        1. Shim

2.   Remove the front pressure valve holder from the           5.   Continue turning the crankshaft slowly clockwise
     i njection pump.                                               until the fuel stops flowing out from the pressure
                                                                    valve holder. Check the position of the crankshaft
                                                                    to the marking on the pulley and engine block at
                                                                    this point. See Fig. 90.
                                                                    If the position is after "Y" (B.T.D.C.) a thinner
                                                                    shims should be used under the injection pump
                                                                    flange. If the position exceeds "Z" (B.T.D.C.) a
                                                                    thicker shims should be fitted instead. (See table

                                                                Engine                Pos. of crankshaft in 
                                                                model           X      Y      Z
                                                                                                    I njection start,
                                                                                                    crankshaft pos.
                                                               MD2010         30,0    24,5   26,5   24,5-26,5 f.o.d.
                                                               M D2020
                                                               up to
                          Fig. 89.                             5101311299 30,0        24,5   26,5   24,5-26,5 B.T.D.C.
       1. Pressure valve holder      4. O-ring                 from
       2. Spring                     5. Copperwasher           5101311300 30,0        26,0   28,0   26,0-28,0 B.T.D.C.
       3. Pressure valve             6. Pump element
                                                               M D2030
                                                               up to
                                                               510101938      30,0    21,5   23,5   21,5-23,5 B.T.D.C.
3.   Remove the pressure valve and replace the pres-           from *
     sure valve holder.                                        510101939      30,0    20,5   22,5   20,5-22,5 B.T.D.C.
                                                               M D2040A

4.   Move the throttle arm to max. position. Turn the          MD2040B
     crankshaft clockwise until the piston in cylinder No.     **868748       30,0    20,0   22,0   20,0-22,0 B.T.D.C.
     1 moves upwards in the compression stoke and              MD2040B
     fuel begins to flow out from the pressure valve (po-      **868778
     sition X in the table below). The work is simplified if   MD2040C        30,0    18,0   20,0   18,0-20,0 B.T.D.C.
     an approx. 50 mm (2 in) "observation tube" is fitted
     on the pressure valve.                                     engine number       - product number

Fuel system

     Note: A change of shim size by 0.1 mm (.0039 in)
     implies that the injection start is moved approx. 1 .
     An increase in shim size reduces the injection
     angle and conversely a decrease in shim size in-
     creases the angle.
     Shims are available in the following sizes: 0.2, 0.3,
     0.4 and 0.5 mm (.0078, .0118, .0157 and .0196 in).
     NOTE! In the event that no shims are required,
     li quid sealing compound should be used.
     Replace the pressure valve. Screw in the pressure
     valve holder by hand. If the pressure valve holder
     will not go in, screw the holder backwards and for-
     wards quickly 1/4-1/2 turn until the pressure valve
     goes in the pressure valve holder. Screw down the
     pressure valve fully by hand until the 0-ring begins
     to be pressed together. Tighten after this with a
     17 mm spanner.

     Tightening torque, see Technical data.
       WARNING! The pressure valve holder must be
       screwed in by hand so that it is possible to feel
       that the pressure valve goes correctly into the
       valve holder. Never use force to screw the valve
                                                               Fig. 91. Measurement of piston position with dial gauge
       holder down since this can damage the pressure
       valve. If the pressure valve cannot be turned in
       the valve holder the pump must be dismantled
       and the same method applied with the pump in a
       completely horizontal position.

                                                                                MD2O10,      MD2030        MD2040
                                                               Crankshaftangle Piston pos.   Piston pos.   Piston pos.
                                                                18B.T.D.C.     -            2.317 mm      2.875 mm
6.   Adjustment of the injection angle can also be made         19 B.T.D.C.    -            2.577 mm      3.199 mm
     by measuring the piston height with a dial gauge.          20 B.T.D.C.    -            2.851 mm      3.539 mm
     The table shows the crankshaft position in degrees         21 'B.T.D.C.    -            3.138 mm      3.895 mm
     when the piston is in a certain position in relation to    22 B.T.D.C.    -            3.438 mm      4.267 mm
     B.T.D.C.                                                   23 B.T.D.C.    -            3.750 mm      4.655 mm
                                                                24 B.T.D.C.    3.636 mm     4.075 mm      5.058 mm
     Carry out the adjustment work as per items 4               25B.T.D.C.     3.937 mm     4.413 mm      5.477 mm
     and 5.
                                                                26 B.T.D.C.    4.250 mm     4.763 mm      5.912 mm
     The table shows the position of the piston In re-          27 BT.D.C.     4.573 mm     5.125 mm      -
     l ation to the crankshaft angle ('B.T.D.C.).

                                                                                MD2O10,      MD2030        MD2040
                                                                                MD 2020
                                                               Crankshaftangle Piston pos.   Piston pos.   Piston pos.
                                                                18 BT.D.C.     -            . 0912 in.    . 1131 in.
                                                                19  BT. D.C.   -            . 1014 in.    . 1259 in.
                                                                20 BT.D.C.     -            .1122 in.      . 1393 in.
                                                                21 BT. D.C.    -            . 1235 in.    . 1533 in.
                                                                22 BT.D.C.     -            . 1353 in.    . 1679 in.
                                                                23 BT.D.C.     -            . 1476 in.    . 1832 in.
                                                                24 BT.D.C.     . 1431 in.   . 1604 in.    . 1991 in.
                                                                25 BT.D.C.     . 1550 in.   . 1737 in.    . 2156 in.
                                                                26 BT. D.C.    . 1673 in.   . 1875 in.    . 2327 in.
                                                                27 BT.D.C.     . 1800 in.   . 2017 in.    -

                                                                                                             Fuel system

Setting engine speed (RPM)                                    2.   Warm up the engine and check the idling speed
Check that the throttle mechanism functions normally.              using a workshop tachometer (see Technical Data
Check that the throttle arm (1) (Fig. moves towards low            for correct idling speed).
idle (2) when the throttle mechanism is in idling position
and moves towards the stop screw at wide open throttle
                                                              3.   If necessary, adjust to the correct idling speed
(WOT) (3) when the throttle mechanism is at wide open
                                                                   using the adjustment screw (2).
throttle (WOT). Adjust the throttle mechanism if neces-
sary. Also check that the air filter and air intake are not
blocked.                                                      4.   Check gap (3) again according to point 1.

        I MPORTANT! The engine speed (RPM) and
        fuel quantity are factory set to give maximum
        output and minimum environmental impact. The-         Engine racing (high idling speed)
        se settings must not be changed                       Warm up the engine and check the engine racing speed
        Seals on the fuel injection pump may only be          using a workshop tachometer when the engine has no
        broken by authorised personnel. Broken seals          l oad at wide open throttle (WOT) (see Technical Data
        must always be resealed                               for correct engine racing speed).

                                                              Adjust if necessary as follows:
                                                              1.   Slacken off the stop screw (3) so that it does not li-
                                                                   mit the movement of the throttle arm (1).

                                                              2.    Run the engine with no load at wide open throttle
                                                                   ( WOT) and adjust to the correct rev speed using
                                                                   the adjustment screw (4) (remember to reseal the

                                                              3.   Adjust the stop screw (3) so that there is a clearan-
                                                                   ce of 0.1 mm between the stop screw (3) and the
                                                                   throttle arm (1) when the throttle mechanism is at
                                                                   wide open throttle (WOT).

                                                              Feed pump
          Fig. 92. Setting engine speed (RPM)                 Dismantling of feed pump
           1. Throttle arm
           2. Adjustment screw, low idling speed              1.   Wash clean round the pump.
           3. Stop screw, wide open throttle (WOT)
           4. Adjustment screw, engine racing
           5. Adjustment screw, maximum quantity of fuel      2.   Close the fuel cocks. Release the fuel connections
                                                                   from the pump.

                                                              3.   Dismantle the feed pump from the cylinder block.
Low idle speed                                                     Empty the pump of fuel.
1.   Check that gap (6) (Fig. 92) is approximately 3 mm
     when the throttle mechanism is in the idling posi-
     tion. If necessary: Slacken off the locknut (7) and
     adjust until the correct gap is obtained with the
     screw (8).

 Fuel system

 I njectors                                                      7.    Fit the fuel leak pipe.

 Replacement of injectors
                                                                 8.   Fit the delivery pipes. Check that they do not come
 1.    Wash clean round the injectors.                                skew, and tighten the nuts.
2.     Release the delivery pipes at the injection pump               Tightening torque: 20-25 Nm (14.7-18.4 ft.lbs).
       and at the injectors. Lift off the delivery pipes to-
3.     Remove the nut on the top of each injector and lift      9.    Start the engine and check that no leakage occurs.
       off the fuel leak pipe.

                                                                Renovating injectors
                                                                1.    Clean the injector internally.
                                                                2.    Place the injector (holder) in a vice. Unscrew the
                                                                      nozzle nut and take the injector apart.
                                                                      Note: Observe care when taking it apart so that the
                                                                      nozzle needle does not drop out.
                                                                3.    Pull out the nozzle needle from the nozzle sleeve
                                                                      and place the parts in cleaning petrol.

                                                                Note: Make sure that the nozzle needles and nozzle
                                                                    sleeves which belong together and are adjusted to
                                                                    each other are not mixed up if several nozzles are
                                                                    cleaned together. To avoid confusion the nozzles .
                                                                    should be placed in a nozzle rack or in different
                                                                4.    Check the nozzle carefully with a lamp magnifier or
                Fig.102. Dismantling of injector                      i n a microscope. Check the other parts also.
      1. Injector              3. Heat shield (MD2030)          5.    When fitting a new nozzle it is important that pre-
      2. Copper packing        4. Insert (MD2O10-2030)
                                                                      serving oil is washed off the nozzle needle and
                                                                      sleeve before the injector is assembled (avoid skin
                                                                      contact with needle's slide surface).
                                                                      Clean the parts in pure alcohol. Check that the
4.                                                                    nozzle needle slides in the sleeve without sticking.
       Unscrew the injectors. Use socket, L = 80 mm.
                                                                6.    Dip the nozzle parts in pure diesel or testing oil and
       Socket width = 22 mm (MD2O10, 2020, 2040),
       socket width = 27 mm (MD2030)                                  put the injector together. Use the original thickness
                                                                      of adjuster washer(s) to set the opening pressure.
       Remove the copper packings under the injectors.
                                                                7.    Check the opening pressure, jet pattern and tight-
       MD2030: Remove the heat shields (3, Fig. 102).                 ness in a nozzle testing device.
       MD2O10, MD2020, MD2030: Remove the inserts
       (4) and the inner copper washers.

5.    Fit a protective cap on the pipe connections on the
      i njectors over the nozzle if the injector is not to be
      fitted immediately.

6.     Fit the new injector.
      Tightening torque: see Technical data.

                                                                                                                  Fuel system

Testing of injectors                                            Checking of injectors
Testing is carried out in a nozzle testing device. The          Jet pattern
opening pressure and tightness are the most important           1.    Pump with the nozzle testing device and check the
part of the test. The jet pattern is more difficult to evalu-        j et pattern. The fuel jet should be conformed and in
ate and does not give a reliable indication of the condi-             li ne with the centre line of the nozzle.
tion of the nozzle.

                                                                2.   Check that the fuel jet has a circular cross section.

      WARNING! Observe care when testing the injec-             Tightness
      tors so that unprotected parts of the body are not        Tightness testing examines potential leakage between
      hit by the fuel jet from a nozzle. The jet has such       the seat of the nozzle needle and the conical sealing
      a powerful impact that it can penetrate into the          surface of the nozzle sleeve.
      skin and cause blood poisoning.
                                                                1.   Wipe off the nozzle pin so that it is dry.
                                                                2.   Pump up the pressure to approx. 2 MPa (20 kp/
                                                                     cm 2 , 284.4 lbf/int) under the injector's opening pres-
                                                                     sure (see Technical data). Hold the pressure con-
                                                                     stant for 10 seconds and check if any fuel drips
                                                                     from the nozzle pin. Wet nozzles can be approved.
                                                                Fit protective caps on the injector's pipe connections
Adjusting the opening pressure, injector                        and over the nozzle heads if the injectors are not to be
                                                                fitted immediately.

    A   T

         Fig. 103. Adjuster washers (7), injector

Press the nozzle testing device's lever slowly down with
the manometer connected until the nozzle opens and
releases the fuel. Read off at that precise moment the
opening pressure.
If the value read off does not correspond with the pre-
scribed value the setting must be changed. This is done
with adjuster washers (Fig. 103).

Note: The opening pressure increases or diminishes
with approx. 1 MPa (10 kp/cm 2 , 142.2 lbf/int) with a
change in the thickness of the adjuster washer by
0.1 mm (.0039 in).

                                           Cooling system

General                                                         Sea water pump
The engines are fresh water cooled and fitted with an           The sea water pump is fitted on the timing gear housing
enclosed cooling system. The system is divided into             at the front end of the engine. The pump is driven via the
t wo circuits.                                                  engine's timing gears. The pump wheel (impeller) is man-
I n the inner circuit (fresh water system) the refrigerant is   ufactured of rubber and is replaceable.
pumped round by a circulation pump which is driven by           Note: The pump wheel will become damaged if the pump
a V-belt from the crankshaft pulley.                            i s run dry.
The fresh water system works at a certain overpres-
sure, whereby the risk of boiling is reduced at high tem-
peratures. A pressure valve opens in the filler cap if the
pressure gets higher than normal.
The temperature of the refrigerant is regulated by a
The percolation in the sea water system is handled by a
gear driven pump of the blade type.
 Heat is transferred from the refrigerant to the sea water
i n a heat exchanger.
As extra equipment the engine can be fitted with a sep-
arate expansion tank.

            Fig. 104. Filler cap for refrigerant

The engines are provided with a thermostat, the sensor
body of which contains wax.
When the engine is cold the thermostat keeps the chan-
nel to the heat exchanger closed. The refrigerant then
passes via a a by-pass pipe directly back to the induc-
tion side of the pump. As the engine heats up the wax
i ncreases in volume and the thermostat gradually opens
the channel to the heat exchanger, at the same time as
the by-pass pipe is closed.
See "Technical data" for opening temperatures.


                                                                                                               Cooling system

   Repair instructions
   NOTE! Close the bottom valve before working on the
   cooling system.

   The refrigerant has the twin purpose of protecting the
   cooling system from freezing and preventing corrosion.
   Use a mixture of 50 % Volvo Penta antifreeze (glycol) and
   50 % pure water (as neutral as possible). This mixture
   prevents freezing down to approx. -40C (-40F) and
   should be used all year round.
                                                                               Fig. 105. Draining of the refrigerant
   Note: At least 40 % antifreeze should be used in the sys-
   tem to ensure satisfactory corrosion protection.
   Mix the antifreeze with water in a separate vessel before
   filling the cooling system.
   For replenishment of the refrigerant see the instruction on
   page 64.                                                         The sea water system
                                                                    Watch out for the penetration of water in the boat!
          WARNING! Antifreeze is hazardous to health                1. Close the bottom cock or the cock on the S-
   0                                                                    drive. Release the cover on the sea water pump
          (dangerous to consume).
                                                                        and let the water run out.
   I n the event that antifreeze is not necessary it is appropri-
   ate to add Volvo Penta anti-corrosion agent 1141526-2.           2.   Release the hose from the sea water pump and
                                                                         sea water filter at the reverse gear and tilt down so
                                                                         that the water runs out.

                                                                    3.   Check if there are additional cocks/plugs at low
   Draining of the refrigerant                                           points on the refrigerant and exhaust pipes.
                                                                         Check carefully that all the water runs out.
   Stop the engine before draining the cooling system.
   The fresh water system
                                                                    4.   Tighten the hoses and cover to the sea water
   1. Unscrew the filler cap. Turn the cap to the first stop             pump.
       and wait a moment before lifting off the cap.
                                                                         Pump out the boat and check that there is no
          WARNING! Open the filler cap very carefully if                 l eakage.
          the engine is hot. Steam or hot liquid may spit

   2.   Connect a hose to the drain cock. Open the cock
        and drain out the refrigerant in a vessel.
        Hand in the mixture to a recovery station if it is
        not to be used again. Never pollute the water.

Cooling system

Replenishment of refrigerant
Flush the cooling system before filling up with re-                                          v
Close all the drain points and fill up with refrigerant to
the correct level. See next page.
Filling should be done with an idle engine. The en-
gine must not be started before the system is vented                           l
and completely filled. If a heater unit is connected to the                                      IN
engine's cooling system the heat control valve must be
fully opened and the unit vented during filling.
Check hoses and connections and seal any leaks.
Note: Fill the system slowly! Filling should not be
done too quickly or else air pockets can form in the sys-
tem. The air should be allowed to flow out through the                                 MD 2010-2040C
filling opening. Check the engine coolant level after run-                              Refrigerant level
ning the engine for some time. Top up coolant if re-

                                                                 Refrigerant temperature too low

                                                                 If the refrigerant temperature is too low this may be be-
                                                                 cause of:
Check the engine coolant level
                                                                 -   Defective thermostat.
                                                                 -   Defective temperature sensor or instrument.
        WARNING! Do not open the engine coolant
        system filler cap when the engine is still hot ex-
        cept in an emergency Steam or hot coolant may
        spray out.
                                                                 Refrigerant temperature too high
                                                                 If the refrigerant temperature is too high this may be be-
Turn the filler cap to the first stop and let any pressure
                                                                 cause of:
escape from the system before removing the cap. Top
up coolant if necessary. For MD2O10-204OA/B the level                Blocked sea water inlet or sea water filter.
must be just under the neck of the filler opening and for            Defective pump wheel in the sea water pump.
MD2O10-2040C between the lower edge of the neck of
                                                                     Too low refrigerant level, air in the fresh water sys-
the filler opening and the level spur (1). Reinstall the fill-
er cap.
                                                                     Slipping or burst belt for the circulation pump.
                                                                     Defective thermostat, temperature sensor or instru-
If a separate expansion tank is installed (optional extra)
the level should be between the MAX and MIN marks.
                                                                     Blocked cooling system.
                                                                     I ncorrectly set injection pump, i.e. injection angle.

                                                                 Refrigerant loss
                                                                 There are two types of refrigerant loss:
                                                                 - Refrigerant loss when running.
                                                                 -   Refrigerant after stopping with a hot engine.
                                                                 Refrigerant loss when running may be because the
                                                                 cooling system is not tight or because air or combustion
                                                                 gases have been forced into the system.

                     MD 2010-2040A/B
                      Refrigerant level

                                                                                                           Cooling system

Checking of pressure valve in filler cap                      2.   Release the hose clips and remove the rubber
                                                                   muffs at the front and back of the heat exchanger.
Special tool: 999 6662                                             Pull out the insert.
1.   Drain off the refrigerant and connect the pressure
     testing device with a nipple to one of the plugged
     holes in the cooling system.                             3.   Flush and clean the insert inside and outside.
                                                                   Clean also the housing.
                                                                   Note: I f there are loose deposits in the insert a suit-
2.   Extend the drain hose from the filler pipe with a             able steel rod can be pushed through the tubes in
     hose the end of which is placed in a vessel contain-          the opposite direction to the flow of water.
     i ng water.
                                                                   NOTE! Make sure that the rod does not damage
                                                                   the tubes.
3.   Apply the pressure and read off the manometer
     when the valve opens (water bubbles in vessel).
     The valve should open at 0.9 kp/cm 2 (12.8 lbf/in 2 ).
                                                              4.   Fit the insert in the heat exchanger. NOTE! Make
                                                                   sure that the insert is positioned correctly. Make
4.   Remove the test equipment. Fit the plug and fill up           sure that the hole in the insert casing comes oppo-
     with refrigerant.                                             site the hole in the housing and that the vent hole
                                                                   comes upwards. The insert is marked with "UP".
                                                                   Place the insert so that its extruding parts are equal
                                                                   at the front and back.

Cleaning of heat exchanger
Clean the heat exchanger insert on signs of blocking          5.   Fit the rubber muffs on the heat exchanger's front
(slow rise in refrigerant temperature).                            and back and tighten the hose clips. Connect the
                                                                   hose from the sea water pump and tighten the clip.
NOTE! Check/clean the sea water filter first. Check also
the sea water pump's impeller and sea water intake.
                                                              6.   Fill up with refrigerant.
0     I mportant! Close the bottom valve before
      working on the cooling system.

                                                              7.   Open the bottom cock or the cock on the S-drive
1.   Drain off the water in the sea and fresh water sys-           and start the engine. Check that no leakage occurs.

             Fig. 106. Heat exchanger insert

Cooling system

Replacing the circulation pump
1.   Drain off the refrigerant from the engine (fresh wa-
     ter system).

2.   Release the alternator and remove the drive belt.
     MD2030, MD2040: Remove the clamp for the alter-

3.   Remove the rubber hoses to and from the pump.               Fig. 108. Application of sealing compound (silicon)

4.   Release the electric cables to the temperature re-
     l ay.
                                                            3.    Apply sealing compound (silicon, Volvo Penta part
                                                                  No. 1161277-7) on the cylinder block as per Fig.
                                                                  108, shaded area.
                                                                  Fit the refrigerant pump with a new gasket.

                                                            4.    MD2030, MD2040: Fit the clamp to the alternator.

                                                            5.    Fit the rubber hoses at the pump's inlet and outlet.
                                                                  Tighten the hose clips.

                                                            6.    Fit the drive belt. It should be possible to press the
                                                                  belt down approx. 10 mm (.40 in) between the pul-
                                                                  l eys.
          Fig. 107. MD2030. Circulation pump

                                                            7.    Connect the contact piece to the temperature relay.
5.   Remove the pump's attachment screws and lift off
     the pump.                                              8.    Fill up with refrigerant. Start the engine and check
     MD2030: Remove the back piece (plate), spring,               that no leakage occurs.
     and thermostat.

                                                            Replacing the pump wheel in the sea
1.   Clean the mating surfaces on the pump and cylin-       water pump
     der block.
                                                            Close the bottom cock, or the cock on the S-drive
                                                            before working on the cooling system.
2.   MD2030: Place the thermostat and spring in the         1.    Dismantle the pump's end cover and drain off the
     pump. Fit the back piece (plate) on the pump with a          water in the sea water system.
     new gasket.

                                                                                                       Cooling system


                                                                       M D2040                    MD2O10-2020

           Fig. 109. Replacing the pump wheel

2.   Pull and twist out the pump wheel (impeller) with a
                                                                               M D2030
     pair of universal pliers.
                                                                      Fig.110. Positioning of the thermostat
3.   Clean the housing internally. Grease in the pump                             1. Cover
     housing and inside of the cover with a little grease.

4.   Press in the new wheel with a rotational motion         3.   MD2O10, MD2020: Release the exhaust pipe and
     (clockwise). Fit the sealing washer on the outer             remove the heat exchanger housing complete. Re-
     end of the centre of the wheel.                              move the spring and lift out the thermostat from the

5.   Fit the cover together with a new gasket.
                                                             4.   MD2040: Remove the cover (1) on the front left-
                                                                  hand side of the heat exchanger. Remove the rub-
6.   Open the bottom cock, or the cock on the S-drive.            ber ring.
     Start the engine and check that no leakage occurs.

                                                             Checking the thermostat
                                                             1.   Check that the thermostat closes completely.
Thermostat                                                   2.   Heat up water in a vessel to 68C 1 154.4F
Replacing the thermostat                                          ( MD2O10, MD2020), or to 75C / 167F (MD2030,
Note: On MD2030 the thermostat is accessible after the
                                                             3.   Submerge the thermostat in the water. Check after
circulation pump has been removed. See under head-
                                                                  at least 3-5 minutes that the thermostat is still
i ng "Replacing the circulation pump" on page 66.
Other engines:
                                                             4.   Raise the temperature to boiling point (100C /
1.   Remove both battery leads. Drain off the water in            212F). Check after 3-5 minutes that the thermo-
     the fresh water system.                                      stat has opened at least 6 mm /.02362 in
                                                                  ( MD2O10, MD2020), or to 8 mm /.3149 in
                                                                  ( MD2030, MD2040).
2.   MD2O10, MD2020: Drain off the water in the sea
     water system. Remove the alternator.                    Replace the thermostat if these specifications are not
                                                             met. NOTE! If the thermostat does not close completely
                                                             the engine will run at too low a temperature.

                                      Electrical system

General                                                            The electrical system also includes as accessories re-
                                                                   l ays for the monitoring of the engine's refrigerant tem-
The engines are fitted with AC generators. The system              perature and oil pressure.
voltage is 12V.
                                                                   The electrical system is illustrated in two ways. The wir-
MD2010A, -2020A, -2030A and -2040A are fitted with a               i ng diagram (page 80) shows the wiring, cable areas
1,5-pole* electrical system, while MD201OB/C, 2020B/               and colours.
C, 2030B/C and 2040B/C have a one-pole system.                     Where respective parts are positioned on the engine is
* Note: One-pole during the start procedure via an                 shown in the figures below.
earthing relay.

                       Positioning of electrical components on the engine


                            Fig. 111. Positioning of electrical components on the engine

                                 1.   Starter motor                       8. Fuses (4 pcs),
                                 2.   Earthing relay (A-version)             max. 15A (-) (A-version)
                                 3.   Glow plug                           9. Oil pressure relay,
                                 4.   Alternator                             (accessory)
                                 5.   Starter relay                      10. Oil pressure sensor
                                 6.   Glow relay                         11. Refrigerant temperature relay
                                 7.   Fuses (4 pcs),                         (accessory)
                                      max. 15A (+)                       12. Refrigerant temperature sensor

                                                                                                        Electrical system

Fuses                                                       Connection of sensor system
                                                                    I mportant! Stop the engine and then switch off
The fuses are placed in the relay box at the rear left-
hand side of the engine. The fuses disconnect the cur-
                                                            0       the current with the main switches before
                                                                    working on the electrical system.
rent when overloaded.
MD2010A, -2020A, -2030A and -2040A are fitted with          1.    Release the yellow sensor conductor from connec-
two fuse blocks each with four fuses (15A) for plus (+)           tion B+ on the alternator.
and minus (-) .                                             2.    Splice the conductor (yellow, 1.5 mm 2 , 16 AWG)
MD201OB/C, -2020B/C, -2030B/C and -2040B/C have                   and connect it to the batteries' plus pole (+).
only one fuse block with four fuses (15A) for plus (+).
Re-connect the electrical system, after inspection and
work, if one fuse has triggered by moving the cable con-
nection to the next contact.

                                                            Charging distributor
                                                            As an accessory the engine's standard alternator can
                                                            be provided with a charging distributor. Two separate
                                                            battery circuits can thereby be charged simultaneously.
Relays                                                      The charging distributor separates both groups from
                                                            each other so that the engine's start battery is main-
The relays are placed in the relay box on the rear left-    tained fully charged even if the "accessory batteries"
hand of the engine.                                         are weak or almost flat.
The start and glow functions are controlled via their own
switching relay. These relays are identical and therefore
i f necessary can be interchanged.

Voltage regulator with sensor system
The voltage regulator to the standard alternator (14V/
60A) is provided with a sensor system.
The sensor system compares the charge voltage be-
tween the alternator's connections B+ and 13- with that
between the batteries' plus and minus poles. The volt-
age regulator then compensates any voltage drop in the
cables between alternator and batteries by increasing
the charge voltage when necessary from the alternator.
On delivery from Volvo Penta the sensor system is not
activated. Connection has, however, in all probability
been carried out in connection with the installation of
the engine.
                                                            Fig. 112. Connection of sensor system to standard al-
                                                            ternator, principle drawing
                                                            1.   Sensor conductor (yellow, 1.5 mm 2, 16 AWG)
                                                            2.   Charging distributor (accessory)
                                                            3.   Alternator
                                                            4.   Fuse panel (accessory)
                                                            5.   Starter motor
                                                            6.   Main switch
                                                            7.   Accessory batteries (accessory)
                                                            8.   Start battery (engine)

Electrical system

I mportant information on the                                  3.   For starting with auxiliary battery, see instruc-

                                                                    tions of page 71.
electrical system
      I MPORTANT! Stop the engine and switch off the           4.   Electric cables
      current with the main switch before working on
      the electrical system.                                        Never make holes in the cable insulation to conduct
                                                                    measurements. In a corrosive environment such as
1.   Main switch
                                                                    i n a boat it takes approx. 2 years for thin cables to
     Never break the current circuit between the altern-            oxidise off via the hole.
     ator and battery when the engine is running. The               If a hole must be made in the insulation, it should
     main switch must never be switched off before the              be sealed with an appropriate glue afterwards.
     engine has stopped. If the current is broken while
     the engine is running the voltage regulator can be
     destroyed and the alternator seriously damaged.           5.   Connection of extra equipment
     For the same reason the charging circuits must not             All extra equipment should be connected to a sepa-
     be switched over when the engine is running. For               rate terminal box and be fused. Extra power points
     simultaneous charging of two separate battery cir-             directly from instrument panels should be avoided.
     cuits it is possible to fit a Volvo Penta charging dis-        Permissible extra outlets are a total of max. 5A
     tributor to the standard alternator (accessory).               (for all instrument panels together).

2.   Batteries
     Never switch the batteries plus and minus poles
     when fitting the batteries. This can result in serious
     damage to the electrical equipments. Compare with
     the wiring diagram. The battery poles should be
     well cleaned and the lead lugs always tight and
     well greased to ensure good contact.
     Quick charging of batteries should be avoided. If
     quick charging must be used, then both battery
     l eads should always be removed first.
     NOTE! Follow the relevant safety instructions when
     charging batteries. During charging the cell plugs
     should be unscrewed but remain in the plug holes.
     Ventilate well, especially if the batteries are
     charged in a closed room. Always switch off the
     charging current before the charge clamps are re-
     l eased.

       WARNING! The battery compartment must
       never be exposed to a naked flame or electrical
       sparks. Never smoke in the vicinity of batteries.
       Hydrogen gas develops during charging which
       when mixed with air forms oxyhydrogen gas.
       This gas is highly inflammable and very explos-
       i ve.
       Always use protective goggles when charging
       and handing batteries.
       The battery electrolyte contains strongly corros-
       i ve sulphuric acid. In the event of skin contact,
       wash with soap and plenty of water. If battery
       acid gets in your eyes, rinse immediately with
       plenty of water and contact a doctor immediately.

                                                                                                       Electrical system

Galvanic corrosion                                           Electric welding
MD201OB/C, MD2020B/C, MD203OB/C, MD204OB/C                   Remove the plus and minus leads from the batteries,
The engine's flywheel housing and transmission (re-          and then remove all cables to the alternator.
verse gear/S-drive) are electrically insulated from the      Always connect the welding clip to the component
engine. Note the fitting sequence on the screw union         which is to be welded and as close to the weld point as
(Fig. 113). The insulation sleeve pos. 1 is only fitted on   possible. The clip must never be connected to the en-
one of the screws (optional screw).                          gine or so that the current can pass over a bearing.

Q      WARNING! The flywheel housing or transmission         0 On completion of welding: Always connect the
       (reverse gear alt. S-drive) must under no circum-       cables to the alternator before the battery leads
       stances be earthed. Earthing of these compo-            are replaced.
       nents can result in serious damage as a result of
       galvanic corrosion.

                                                             Repair instructions
                                                             Starting with auxiliary battery
                                                ,u     i           WARNING! The batteries (especially the auxiliary
                                                J  -
                                                                   battery) contain oxyhydrogen gas which is very
                                                                   explosive. A spark, which can occur if the auxili-
                                                                   ary battery is incorrectly connected, is sufficient to
                                                                   cause the battery to explode and result in injury.
                                                             Note: If the start battery has frozen it must be thawed
                                                             first before a start attempt is made with the auxiliary
                                                             battery. Check that the battery is not damaged before
                                                             connecting it again.

                                                             1.   Check that the auxiliary battery's rated voltage cor-
                                                                  responds to the engine's system voltage (12V).

                                                             2.   Connect the red auxiliary lead (+) to the auxiliary
                                                                  battery and then to the flat battery. Then connect
                                                                  the black auxiliary lead (-) to the auxiliary battery,
                                                                  and finally to a point some distance from the flat
                                                                  batteries, e.g. at the main switch on the minus lead
                                                                  or at the minus lead's connection on the starter mo-
                                                                  tor (2-pole electrical system), or at the minus lead's
                                                                  connection on the engine (one-pole system).

                                                             3.   Start the engine. NOTE! Do not touch the con-
                                                                  nection during the attempt to start (risk for
                                                                  sparks) and do not lean over any of the bat-

 Fig. 113. Electrical insulation (A) of the flywheel hous-   4.   Remove the leads in exactly the reverse order to
i ng and transmission                                             the way they were connected. NOTE! The ordin-
                                                                  ary leads to the standard battery must absolute-
1. Insulation sleeve   2. Insulation washer                       l y not be disconnected.
3. Washer

Electrical system

Checking the battery leads                                 Procedure
Set the multimeter for voltage testing and then connect
the multimeter between the battery's plus and minus        A     WARNING! Disconnect the current and remove
pole. Run the engine at approx. 2000 rpm. Read off and           both battery leads before working on the charging
note the voltage over the battery poles.                         circuit.

The alternator provides approx. 14.0 V:                     If the voltage drop during any of the tests as per the
                                                           i tems above exceeds 0.2 V the lead connections must
Conduct test as follows:                                   be removed and cleaned from oxide etc. Spray the con-
Connect the multimeter between the alternator's B+ and     nections with a moisture repellant contact oil (Volvo
B- connections.                                             Universal oil, part. No. 1161398-1) or the like and tight-
                                                           en the connection again.
Run the engine at approx. 2000 rpm. The alternator
should provide 14.0-14.4 V. The total voltage drop         Rectify the connections at the battery, main switch,
must not exceed 0.4 V.                                     starter motor, alternator, glow relay and glow plug.

Voltage drop less than 0.2 V:
Battery leads in good condition.                           Alternator
Voltage drop more than 0.3 V:                              Checking and troubleshooting of the al-
Conduct check of battery leads.                            ternator
                                                           Dismantle the alternator's electrical connections.
                                                           Spanner widths 8 and 10 mm.
The alternator provides more than 14.4 V:                  Remove the alternator belt. Dismantle the alternator.
See items "Checking and troubleshooting of alternator"     Spanner widths 1 1/16"; 5/8"; 12 mm and 13 mm.
and "Checking of the regulator".                           Release the voltage regulator's connections at the alter-
                                                           nator's B+ connection. Remove the flat pin at connec-
                                                           tion B+ and D+. Remove the cap on the W connection.
                                                           Bend the plastic guard's attachment lugs alternately off
                                                           the alternator. Release the regulator's two connection
Checking of positive battery lead                          cables to the diode bridge. Use long-nose pliers or poke
Connect the multimeter between the alternator's B+         out the cable lugs with a screwdriver. Do not pull the
connection and the battery's plus pole.                    cables!
Run the engine at approx. 2000 rpm. The voltage drop
must not exceed 0.2 V. If the voltage drop exceeds this
value the lead connections must be rectified as per the
"Procedure" below.                                         Replacement of carbon brushes in the
After this carry out a test as per "Checking of negative   alternator
battery charging".
                                                           Unscrew the voltage regulator. Unscrew the brush hold-
                                                           er. Check the length of the carbon brushes. Replace the
                                                           brushes if they are 5 mm (.1968 in) or shorter. Carbon
                                                           and holder are replaced as one unit. Unsolder the con-
                                                           nection cables and solder on the new ones with an
Checking of negative battery lead                          acid-free soft solder.
Connect the multimeter between the alternator's B-
connection and the battery's minus pole (-).
Run the engine at approx. 2000 rpm. The voltage drop
must not exceed 0.2 V. If the voltage drop exceeds this
value the lead connections must be rectified as per the
"Procedure" below.

                                                                                                      Electrical system

Checking of the regulator                                     Dismantling the diode bridge

Special tool: Regulator tester 884892-1                       I n order to check the diode bridge and stator windings
                                                              the diode bridge should be dismantled.
Check before testing that the instrument's batteries
have the correct voltage. Press in the button "Test" and      Unsolder the three stator windings. Avoid excessive
check that the green lamp ("Batt.") lights. Replace the       heat since this can damage the diodes. Release the
batteries (2 pcs alkaline, 9 V) if the lamp does not light.   nuts (note how the washers and nuts are fitted).

The batteries are in a compartment underneath the in-         Check measurement of the diode bridge
strument.                                                     Set the multimeter in the position "Diode test". Be very
                                                              careful to obtain good contact with the probes during all
Connect the tester's grey cables to the carbon.

Connect the tester's brown cable to the regulator's yel-
l ow and brown cables which should be put together dur-       Checking of the B+ diodes
 ing the test.                                                Connect the measuring instrument's positive probe to
                                                              one of the stator winding connections (1-2-3). Connect
                                                              the instrument's negative probe to the diode plate's B+.
Connect the tester's black cable to the regulator's black     Read off the instrument. A normal value should lie be-
                                                              tween 450 and 650 mV, which is the voltage drop over
                                                              the diode. An other value indicates a defective diode.
Press the "Test" button and at the same time turn the         Check the other B+ diodes by moving the positive
rheostat from the "0" marking to the "1" marking.             probe to the respective connection (1-2-3).
                                                              Check the B+ diodes in the opposite direction of current
                                                              flow by switching the position of the positive and neg-
                                                              ative probes. Carry out the same measurement proced-
Regulator in good condition                                   ure as above. The instrument should during this meas-
The red and green lamps should light from "0". The red        urement show a one "1" (to far left). If the instrument
lamp should go off at the "1" marking.                        shows another value the diode is defective.

Faulty regulator                                              Checking of the B- diodes
Replace the regulator if the red lamp lights constantly       Connect the instrument's positive probe to the diode
when the rheostat is turned, or if it does not light in any   plate's B- connection and the instrument's negative
position.                                                     probe to the respective stator winding connection
Note: The "2" marking on the tester is not used for this
type of regulator.
                                                              Read off the instrument as before. A normal value
                                                              should lie between 450 and 650 mV. Another value in-
                                                              dicates a defective diode.
Check measurement of rotor winding
After the regulator and carbon brushes have been re-
moved it is possible to measure the resistance of the ro-
Set the measuring instrument in position Q. Make sure
that the probes have good contact between the slip
rings. The resistance of the rotor should be 3.0-5.0 Q.
Check also that no earth fault occurs by measuring be-
tween slip ring and earth.

Electrical system

Check the 13- diodes in the opposite direction of current     NOTE! Check first the inner resistance in the measuring
flow by switching the position of the positive and neg-       cables. When the measurement between the stator
ative probes. Carry out the same measurement proced-          windings is carried out the measuring cable's inner re-
ure as above.                                                 sistance (e.g. 0.10 Q) must be deducted from the value

The instrument should during this measurement show a
one "1" (to far left). If the instrument shows another val-   Measure between all winding connections (three meas-
ue the diode is defective.                                    urements). The resistance should lie at 0.10 S2.

Note: If any diode is defective the entire diode plate        Measure also against the alternator material by con-
must be replaced.                                             necting the instrument in position S2. Measure between
                                                              the respective winding and the material. The instrument
                                                              should during this measurement show a one "1" (which
                                                              i mplies infinite).

Checking of the D+ diodes                                     I f the instrument shows another value the stator winding
The diode plate's three magnetising diodes are check          is defective.
according to the same principle as above.

                                                              Note: If any stator winding is defective the stator
Connect the measuring instrument's positive probe to          must be replaced as a complete unit.
the respective connection for the stator winding (1-2-3)
and the instrument's negative probe to D+. The voltage
drop for the respective diode should be between 450
and 650 mV.

Check the D+ diodes in the opposite direction of current
flow and switch the positions of the positive and nega-
tive probes. Carry out the same measuring procedure
as above. The instrument should show a one "1" (to far        Starter motor
l eft). If the instrument shown another value the diode is
defective.                                                    General
                                                              The stator motor is a DC series motor. The starter gear
                                                              i s controlled by a magnet and is moveable in an axial
Note: If any diode is defective the entire diode plate
must be replaced.                                             direction on the rotor shaft.
                                                              On engine MD2040 the starter motor is provided with a
                                                              reduction gear. This enables a higher torque.

Check measurement of the stator windings
When the diode bridge is removed it is possible to
measure the stator windings with the multimeter set to
the "Buzzer" position.
Measure the resistance between respective windings.

                                                                                                   Electrical system

Dismantling of the starter motor
1.   Remove both battery leads.
2.   Release the electric cables to the starter motor.
3.   Dismantle the starter motor's attachment screws
     and lift off the starter motor.

Stripping of the starter motor
                                                                 Fig. 117. Dismantling of the stator housing
1.   Clean the exterior of the starter motor.

                                                          5.   Remove the brush holder plate. Remove the stator
                                                               housing from the rotor and front bearing shield; on
                                                               2040 from the gear housing.

          Fig. 115. Stripping of the starter motor                    Fig. 118. Dismantling of the rotor

2.   Remove the magnet.                                   6.   Remove the coupling arm and rotor.
                                                               MD2040: The coupling arm is fitted in the gear
3.   Remove the protective cover from the rear bearing
     shield. Remove the lock ring and where appropriate
     the intermediate washer(s).

                                                                   Fig. 119. Dismantling of the starter gear

                                                          7.   Remove the starter gear as per Fig. 119. First re-
                                                               move the lock ring by tapping down the contact ring
                                                               with a suitable mandrel.
                                                               MD2040: The starter gear is fitted in the gear hous-
       Fig. 116. Dismantling of the bearing shield
                                                               i ng.

4.   Remove the rear bearing shield.

Electrical system

Inspection of the starter motor                                Assembly of the starter motor
Troubleshooting on the starter motor should be handed          Assembly is carried out in the reverse order to strip-
over to an authorised electrical workshop which disposes       ping.
over the necessary test equipment.                             Connect + and - from a 12 V battery to the terminal on
                                                               the magnet and check that the starter gear is pushed
1.   Test the rotor with respect to winding flash-over and     forward to the gear stop.
     failure with the test equipment for this purpose.

                                                               Fitting of the starter motor
                                                               1.   Place the starter motor in position in the flywheel
                                                                    housing and tighten it.
                                                               2.   Connect the electric cables to the starter motor.
                                                                    See the wiring diagram on page 80-86.
                                                               3.   Connect both battery leads.

          Fig. 120. Checking of the commutator

2.   Check that the mating surfaces for the electric
     brushes on the commutator are smooth and free
     from dirt and oil. If the commutator is damaged or
     burnt it can be polished with sandpaper No. 500 or        Electrical components
                                                               Relay box with fuses
     Measure the commutator with a dial gauge. Max.
     permissible radial distortion is 0.05 mm (.0019 in).      The A-version has two fuse blocks each with four fus-
                                                               es (15A) for plus (+) and minus (-) placed on the relay
3.   Check that the commutator's insulation lies at least      box at left-hand rear side of the engine.
     0.2 mm (.0078 in) below the laminated surface. Cor-
     rect if necessary. See Fig. 120.                          The B/C-version has one fuse block.
                                                               The fuses disconnect the current in the event of over-
                                                               l oading.
                                                               Re-connect the electrical system of a fuse has blown
4.   Check the linearity of the rotor. Brace the rotor be-     by moving the cable connection to the next contact.
     tween spikes and measure the radial distortion on
     the rotor frame with a dial gauge. Max. permissible
     radial distortion is 0.08 mm (.0031 in).
     Note: The radial distortion is half of the read value.
5.   Check the cogs on the starter gear. Replace dam-
     aged gear. Check also the starter gear ring if the
     gear is damaged.

Field winding
Check with a test instrument that there is no failure in the
winding. If the field winding is defective it should be re-

                                                                            Fig. 121. Relay box with fuses
                                                                                1. Fuse block + (1 5A)
                                                                                2. Starter relay
                                                                                3. Glow relay

                                                                                                Electrical system

Relays                                                   Sensors
Oil pressure relay - alarm                               Note: Sensors are only available with "De Luxe"
                                                         i nstrument panels.

                                                         Oil pressure sensor

              Fig. 122. Oil pressure relay

Contact type: Normally open. The contacts close if the
oil pressure in the engine drops below 0.3  0.15 bar
(4.18 t 2 psi).
Note: Checking of the closing point should be conduct-                Fig. 125. Oil pressure sensor
ed with falling pressure.

                                                         Resistance testing: Measure with falling pressure and
                                                         with instrument connected. Measure with ohmmeter
                                                         class 1 at +20 C (+68F)

                                                         Pressure   0 bar (0:             10 +3 /-5 Q
Refrigerant temperature relay - alarm
                                                                    2 bar (27.9 psi):     52 4Q
                                                                    4 bar (55.8 psi):     88  4 Q
                                                                    6 bar (83.7 psi):     124 5Q

                                                         Refrigerant temperature sensor

        Fig. 124. Refrigerant temperature relay

Contact type: Normally open. The contact closes if the
refrigerant temperature rises over 95C  3C (203F 
Note: Checking of the break point should be conduct-
i ng with rising temperature.

                                                                Fig. 126. Refrigerant temperature sensor

                                                         Resistance sensor: Measure with the sensor sub-
                                                         merged to the hexagonal screw for three minutes in cir-
                                                         culating liquid and with the current switched on.
                                                         Temp. 60C (+140F):      134.0 13.5 S2 (t4C, t7.2F)
                                                               90C (+194F):      51.2 4.3 Q    (t4C, 7.2F)
                                                                100C (+212F):    38.5 3.0 S2   (t40C, t7.20F)

Wiring diagram

                            Engine MD2010A, MD2020A, MD2030A, MD2040A


                              0      0

      1.   Battery                        9. Glow relay                           16. Refrigerant temperature relay (normally
      2.   Main switch                   10. Protective diode                         open, closes at 95C 3C, 203,2 Ft5.6F )
      3.   Startermotor                  11. Fuses (4 pcs), max. 15A (+)          17. Refrigerant temperature sensor
      4.   Earthing relay                12. Fuses (4 pcs), max. 15A (-)          18. Connector, 16-pole
      5.   Earth rail                    13. Splice
      6.   Glow plug*                    14. Oil pressure relay, engine (normally
      7.   Alternator                        open, closed at 0.3 bar 0.1 bar
      8.   Starter relay                 15. Oil pressure sensor
     * MD2O10: 2 pcs. Other engines: 3 pcs

     Cable colours
     BL  =      Blue            OR           Orange
     LBL =      Light blue      R            Red
     BN =       Brown           SB           Black
     LBN =      Light brown     W            White
     GN =       Green           Y            Yellow
     GR =       Grey

     Cable areas in mm 2 are given after the colour code in the wiring diagram.
     Areas not given = 1.0 mm 2.
     Dashed cables are not included from Volvo Penta.

                                                                                                                                                 Wiring diagram

             Engine MD201OB/C, MD202OB/C, MD203OB/C, MD204OB/C

                      4    16                      1         6                                                   11       15   10   14   5 13

                                                            O                                                         3             3    m

                                     C) 0 n                                                                     12



                                R/Y 2.5
             30       87
                                                                  86   85

             86 -85

                                                            R25   30    87         R 2.5
                                                                                               1    1





 1.   Battery                              7.     Glow relay                           12.                  Refrigerant temperature relay (normally
 2.   Main switch                          8.     Fuses (4 pcs), max. 15A (+)                               open, closes at 100C t2C, 212F t3.6F)
 3.   Starter motor                        9.     Magnetising resistance (330/9W)      13.                  Refrigerant temperature sensor
 4.   Alternator                          10.     Oil pressure relay, engine (normally 14.                  Connector, 16-pole
 5.   Glow plug*                                  open, closed at 0.3 t0.1 bar)
 6.   Starter relay                       11.     Oil pressure sensor
 MD2O10: 2 pcs. Other engines: 3 pcs

Cable colours
BL  =      Blue                 OR              Orange
LBL =      Light blue           R               Red
BN  =      Brown                SB              Black
LBN =      Light brown          W               White
GN =       Green                Y               Yellow
GR =       Grey

Cable areas in mm 2 are given after the colour code in the wiring diagram.
Areas not given = 1.0 mm 2 .
Dashed cables are not included from Volvo Penta.


    Wiring diagram

                                           Instrument panel, alternative "B"
                                           MD201OB/C, MD2020B/C, MD2030B/C, MD204OB/C
                                           * (with key switch)

        I  0 of



                                               5  6  7
                           11                  0 0 (9 (9
                                               rFr>P       a         enr   G                        1

                                                                                             - 12



              4                                                                                         ER

                      2    4    6                          15   14    5    7   8        9    V 11            9   3   122   13


                                                    Return spring               1. I nstrument lighting
                                                                                2. Tachometer with built-in hour counter (accessory),
                                                                                   alt. blind plug
                                                                                3. Connector for connection of extra warning display
                                                    II I                           (accessory)
                                                                                4. Electronics unit (alarm)
   Return spring
                                                                                5. Warning lamp, refrigerant temperature
                                                                                6. Warning lamp, oil pressure
                                                                                7. Warning lamp, charging
                                                                                8. Control lamp, glowing
                                                                                9. Switch, instrument lighting
                                                                               10. Switch -Alarm test/Acknowledging
                                                                               11. Key switch
   Cable colours
                                                                               12. Alarm
   BL             Blue                                                         13. Connector for connection of neutral position switch
   BN            Brown                                                            (accessory)
   GN             Green                                                        14. 1 6-pole connection
   GR             Grey
   OR            Orange
   R             Red
   SB            Black
   VO            Violet
   W              White
   Y             Yellow

   Cable areas in mm 2 are given after the colour code in the wiring diagram.
   Areas not given = 1.0 mm 2

                                                                                                                                     Wiring diagram

                                      I nstrument panel, alternative "C"
                                               MD2010A, MD2020A, MD2030A, MD2040A

                                                                                                                       SB 1 0



                                Return spring                   6       9   8    7   4   1    5   2



                    $ 15a15b 305019

 1. I nstrument lighting                            BLISS15

 2. Voltmeter                                                 BUY 1.5

 3. Oil pressure gauge                                                          2    6   5    4   14 15   8    7   3   16       9   10   12 13   1

 4.  Refrigerant temperature gauge
 5. Warning lamp, refrigerant temperature             16                                                      17
 6.  Warning lamp, oil pressure
 7.  Warning lamp, charging                                                 Cable colours
 8.  Control lamp, glowing                                                  BL           Blue
 9.  Electronics unit, alarm
                                                                            BN       -   Brown
10.  Switch, instrument lighting
                                                                            GN       =   Green
11.  Switch - alarm test
                                                                            GR          Grey
12.  Tachometer
                                                                            OR       -   Orange
13.  Key switch
                                                                            R            Red
14.  Alarm
     Connector for connection of neutral position switch                    SB           Black
     (accessory)                                                            VO           Violet
16. 2-pole connection (for extra panel)                                     W           White
17. 1 6-pole connection                                                     Y           Yellow


   Wiring diagram

                                                     Instrument panel, alternative "C"
                                                     MD2010B/C, MD2020B/C, MD2030B/C, MD204OB/C


                                                     6                                             5

                                                                      + - +

                                                7            8         9        10                     11
                                                0 (9 (9 (9
                                                W        a            BAT       &OW



                                                                                                                                                     avw is

                                                                                                                                                     atir   U

   QC cc                                                         k,


              2                                          S        u    S                                                  12 13             11   8

                                                                                              1.   I nstrument lighting
                                                                                              2.   Voltmeter
                                                                                              3.   Oil pressure gauge
                                                                                              4.   Refrigerant temperature gauge
   Return spring                                                                              5.   Connector for connection of extra warning display
                                                                                              6.   Electronics unit (alarm)
                                                                                              7.   Warning lamp, refrigerant temperature
                                                                                              8.   Warning lamp, oil pressure
                             S 15815b 3050 19
                                                                                              9.   Warning lamp, charging
   Cable colour
                                                                                             10.   Control lamp, glowing
                   BL        Blue                                                            11.   Switch, instrument lighting
                   LBL       Light blue                                                      12.   Switch - alarm test/Acknowledging
                   BN        Brown                                                           13.   Tachometer with built-in hour counter (accessory),
                   LBN       Light brown                                                           alt. blind plug
                             Green                                                           14.   Key switch
                   GN                                                                       15.   Alarm
                   GR       Grey
                                                                                             16.   Connector for connection of neutral position switch
                   OR       Orange
                   R        Red
                                                                                             17.    16-pole connection
                   SB       Black
                                                                                             18.   2-pole connection (for extra panel)
                   VO        Violet
                   W         White                           Cable areas in mm 2 are given after the colour code in the wiring diagram.
                   Y        Yellow                          Areas not given = 1.0 mm

                       Extra equipment (accessories)
G eneral
Extra equipment which is driven with V-bet*,s via the                       The following diagram shows the permissible power
engine's crankshaft result in an increased load on the                      takeout at a certain positioning of the pulley and extra
crankshaft. It is therefore important that the axial posi-                  equipment.
tion of the pulley on the crankshaft and the positioning
of the equipment in relation to the crankshaft are adjus-
ted to the power takeout of the extra equipment.

                                          R (N)








                                    0     -                                                                                d (mm)
                                        70    80     90        100 110 120 130 140 150                               200

                                              320        330      340   350    0    10    20    30    40

                                  310                                                                                     50


                                  290                                                                                     70

                                   280                                                                                    80

                                   270                                                                                    90

                                   260                                                                                    100

                                   250                                                                                    110

                                   240                                                                                    120

                                   230                                                                                    130

                                              220        210      200   190   180   170   160   150   140

                                                                 Fig. 127. MD 2010.


                                                                                                          ............................................... ............................... ~
.............................. ..........................................................................








      ...................................................................................................................... ..................................................................










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                                                                            AB Volvo Penta
                                                                           Customer Support
                                                                              Dept. 42200
                                                                         SE-405 08 Gothenburg

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