Piston and connecting rod assembly

To remove and to fit

13-3

Special tools:

Guide pin, 21825 843

Retainers, 21825 844

To remove

1  Disconnect the batteries, stop the supply of the fuel

and drain the engine lubricating oil from the sump

2  Drain the cooling system.

3  Remove the relevant cylinder head, operation 12-9.

4  Remove the lubricating oil sump, operation 19-1 or,

for new engines, operation 19-5.

5  For early engines, remove the sump adaptor,

operation 19-3.

6  If necessary, release the bolts which retain the

lubricating oil pump and remove the lubricating oil

pump, operation 19-7.

7  Hold the relevant cylinder liner with the retainers,

21825 844, as necessary.

8  Turn the crankshaft until the selected assembly of

the piston and connecting rod is at the bottom of its

stroke and remove the nuts of the big end bolts.

Remove the bearing cap and fit the guide pin, 21825

843, on to one of the big end bolts.  Push carefully the

assembly out through the top of the cylinder.

Caution:  There is a danger that the connecting rod

could fall against the cylinder liner and break it. The

use of the guide pin, 21825 843, ensures that this

damage cannot occur.

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To fit

Special tools:

Height gauge, 21825 782

Guide pin, 21825 843

Retainer, 21825 844

Piston ring compressor, 21825 845

1  Turn the crankshaft until the relevant crank pin is at

BDC.  Check that the upper half bearing of the big end

is in its position on the connecting rod.  Set the gaps

of the piston rings in the positions shown (A) if the

pistons have four rings.  If the pistons have three

rings, set the gaps as shown (B).  Apply oil to the

crank pin, the upper half bearing and the piston, and

slide the piston ring compressor, 21825 845, over the

lower end of the piston with the tapered section

against the piston rings.  Fit the guide pin, 21825 843,

onto one of the bolts of the big end bearing (C).  It is

recommended that new bolts and nuts are used. 

When the bolts are fitted, press carefully each bolt

into the connecting rod until the bolt head is fully

against the machined face of the connecting rod.

A

12

Caution:  There is a danger that the connecting rod

could fall against the cylinder liner and break it. The

use of the guide pin, 21825 843, ensures that this

damage cannot occur.

B

13

Caution:  If the old bolts and nuts have been used for

the connecting rod, they must first be inspected, for

signs of distortion of the threads, for stress, or for

indications of stretch, etc.  Renew all bolts and nuts

that could be defective.

2  Fit carefully the assembly of the piston and the

connecting rod into its liner.  Ensure that the cutout in

the lower wall of the piston is in the correct

relationship to the piston cooling jet assembly.  Use

the guide pin to pull the assembly through the piston

ring compressor and into the cylinder liner. Ensure

that the piston ring compressor is held, and does not

fall when it becomes free.  Continue to pull the

assembly until the big end bearing is fitted on the

crank pin.  If the piston and the connecting rod are

assembled correctly, the chamfer on the edge of the

bore in the big end is toward the crankshaft web. 

Ensure that there is clearance between the piston and

the cooling jet.

Caution:  During this operation, do not damage the

bearing surfaces of the crank pin and the half

bearings of the big end.

A

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Caution:  If a retainer, 21825 844, is removed to give

a clearance for the piston ring compressor, it must be

fitted again for each operation before the crankshaft is

turned.

3  Fit and tighten the four nuts of the connecting rod,

in the sequence shown (A) to 20 Nm (15 lbf ft) and

then to 40 Nm (30 lbf ft).  The final operation is to

tighten them to 60 Nm (44 lbf ft).  It is recommended

that the new bolts and nuts are used.  Lubricate lightly

the threads and the contact faces before they are

fitted to the connecting rods.

Caution:  The nuts of the connecting rod should be

tightened gradually and evenly.  During this operation

avoid rapid or sudden movements of the torque

wrench.

A

114

4  Ensure that the crankshaft turns freely.

5  Check the end-float of the connecting rods with a

dial test indicator, as shown (B).  The clearance for

each set of two connecting rods, between the big

ends and their relevant crankshaft webs, must be

0,20 mm to 0,40 mm (0.008 to 0.016 in).

6  Repeat the procedure for each assembly of a piston

and a connecting rod.

Check the clearance between the top face of the

piston and the top face of the cylinder bank as follows:

7  Put the setting plate of the height gauge, 21825

782, on a clean surface which is machined and put

the base of the tool over the setting plate.  Align the

button of the dial gauge to make contact with the

centre of the plate.  Set the dial gauge to zero and

tighten the locking screw.

B

197

8  Turn the crankshaft until one of the pistons is

almost at the top of its cylinder and move the setting

plate to the top face of the piston.  Put the base of the

tool on the top face of the cylinder block, as shown

(C).

9  Continue to turn slowly the crankshaft, to allow the

piston to pass TDC.  As the piston passes TDC, make

a note of the reading on the dial gauge; the maximum

deflection of the pointer gives a minimum reading to

indicate the clearance between the top face of the

piston and the top face of the cylinder bank.  The

permissible clearance is from 0,31 to 0,38 mm (0.012

to 0.015 in).  For engines manufactured from July

1998, fitted with piston number CV66887, the

permissible clearance is from 0,31 to 0,75 mm (0.012

to 0.029 in).

B

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10  Check the clearance of each piston in the

cylinders of ’A’ bank, then turn the crankcase until the

cylinders of ’B’ bank are vertical.  Repeat the

procedure to check the clearance of each piston in the

cylinders of ’B’ bank.

Caution:  If not enough clearance is shown on the

dial gauge, the top face of the piston must be

machined to remove the minimum amount of material

which is necessary to give the correct clearance.  This

will not be necessary for engines manufactured after

July 1998 fitted with the piston XCV66887.

11  Fit the cylinder head, operation 12-9.

12  Fit the lubricating oil pump if relevant, operation

19-7.

13  For early engines, fit the sump adaptor, operation

19-3.

14  Fit the lubricating oil sump, operation 19-1 or, for

new engines, operation 19-5.

15  Fill the sump to the correct level with engine

lubricating oil and connect the supply of the fuel.

16  Fill the cooling system.

17  Connect the batteries.

To dismantle and to assemble

13-4

To dismantle

1  Remove the circlips which retain the gudgeon pin. 

2  Push the gudgeon pin out by hand to release the

connecting rod.  If the gudgeon pin is tight, heat the

piston in a tank of warm water.  Keep together each

assembly.

To assemble

Before the connecting rod is assembled, check for

dirt and debris in the passage for the lubricating oil

and clean the passage with compressed air.

1  The gudgeon pin should be a push fit at 20°C

(68°F).  If it is tight in its bore in the piston, heat the

piston in a tank of warm water.  Remove the piston

from the water and use a clean and suitable rag to dry

the bore for the gudgeon pin.  Fit one of the circlips

into its groove in the bore.

2  Give an application of clean engine lubricating oil to

the small end bush, the gudgeon pin and the bore for

the gudgeon pin.

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3  Insert the small end of the connecting rod into the

piston, and ensure that the cut-out in the lower wall of

the piston is on the opposite side to the larger chamfer

in the bore of the big end.

4  Slide the gudgeon pin into the piston through the

small end bush and fit the second circlip into its

groove.

Caution:  When the big-end bolts are to be fitted, the

flat surface, which is machined on the shoulder at the

centre of each bolt, must be away from the bore of the

big end.  The half bearings will then engage correctly

in the bore of the connecting rod. The shoulders of

new bolts do not have the flat surfaces and special

fitting instructions are not needed for them.

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Piston rings

To remove and to fit

13-5

Special tools:

Ring expander, 21825 793

To remove

1  Put the top face of the piston on the bench and use

the ring expander, 21825 793, with the location ring,

21825 874, to remove carefully each piston ring.  Only

increase the ring gaps enough to ensure that the ends

of the rings do not damage the piston. Lift out the coil

spring from the groove for the oil control ring.  Keep

the rings with their relevant piston.

To fit

1  Put the top face of the piston on the bench and

lubricate the grooves for the piston rings.  Use the ring

expander, 21825 793, to fit carefully each piston ring

in the sequence given below.  Only increase the ring

gaps enough to ensure that the ends of the rings do

not damage the piston.

2  Remove the coil spring from its oil control ring and

fit it around the bottom piston ring groove, with the

latch pin inside both ends of the spring, before the oil

control ring is fitted to the piston.  Ensure that the

piston ring gap is at 180° to the latch pin.

The sequence of the assembly of the rings is:

Top

-

Barrel faced molybdenum

surface

Second

-

Chromium plated surface,

counterbore toward top of

piston

Third

-

-

'Ferrox' treated surface,

counterbore toward top of

piston

Bottom

Composite chromium plated

oil control ring

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Piston and rings

Connecting rod

To inspect

13-6    To inspect

13-7

1  Soak the components in a solvent, such as ’Maxan’     1  Clean the assembly of each connecting rod in

or ’Ardrox 667’, to remove the carbon. Wash the

components in clean water and dry them with

compressed air.

kerosene or a degreasing solution, and then check for

cracks in the rod, the big end cap and the big end

bolts.

2  Inspect the piston for wear, deep scratches, cracks     Caution:  It is recommended that the old bolts and

and further damage.  Check that the wear in each

piston ring groove does not exceed the permissible

limits.  If necessary, check the grooves by the use of

new piston rings.

the old nuts of the assemblies of the connecting rods

should be discarded.  Fit always new nuts to new

bolts and lubricate lightly the threads and the contact

faces before they are fitted to the connecting rods.

3  Inspect the piston rings for wear, deep scratches

and signs of leakage.  Discard the top ring if the

surface has large holes or cavities, or if there are

signs that the surface finish has started to break. 

Compare the surface with the surface of a new ring if

necessary.

2  The bolts and the nuts of the assemblies of the

connecting rods must be inspected for signs of

distortion of the threads, for stress or for stretch, etc. 

Renew all bolts which could be defective.

3  Check the small end bush for wear, for roughness

and for deep scratches.  If a bush is damaged, it must

be renewed.

4  Inspect the spring which is behind the oil control

ring.  If the circumference of the spring is excessively

decreased, the spring and the oil control ring must be

renewed as a complete unit.

4  Inspect the half bearings of the big end for cracks,

for scratches and for contamination in the bearing

surfaces. 

5  Check the gap of each piston ring in a new cylinder

liner, or in a portion of the original cylinder liner which

is not worn.  Discard a piston ring with a gap which

exceeds the limits given on page 73 or page 75.

5  Check the alignment of the big end and of the small

end of the connecting rod.  Do not try to correct a

connecting rod which is bent or twisted.

Caution:  When a new cylinder liner has been fitted,

the piston rings must also be renewed. When a new

piston ring is fitted into an original cylinder liner, the

bore of the cylinder liner must be honed or lapped to

break the glazed surface.

6  Check for cracks in the gudgeon pin and check also

its fit in the piston.  The gudgeon pin should be a push

fit at 20°C (68°F).  If the gudgeon pin is loose in its

bore, the assembly must be renewed. 

Caution:  An assembly of a piston and its gudgeon

pin must be renewed if the components do not

conform to the limits given in Fits and clearances at

the end of this section.  If it is necessary to renew a

piston, it is also necessary to ensure that the

clearance is correct between the top of the new piston

and the top face of the cylinder bank by the use of the

height gauge, 21825 782, operation 13-3.

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Fits and clearances - Pistons and connecting rods

Pistons - 4 rings

Gudgeon pin in piston (A1)

(Gudgeon pin to be push fit at 20°C)

Bore in piston (new). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54,999 to 55,004 mm (2.1653 to 2.1655 in)

Gudgeon pin diameter (new) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54,995 to 55,000 mm (2.1652 to 2.1654 in)

Gudgeon pin in piston - clearance (new) . . . . . . . . . . . . . . . . .-0,001 to +0,009 mm (-0.00004 to +0.00036 in)

Top groove in piston

(wedge shaped for top ring CV 5907)

Diameter over 3,302 mm (0.1300 in) dia. Rollers  . . . . . . . . . . . 136,073 to 135,855 mm (5.3572 to 5.3486 in)

Piston clearance at TDC (A2)

Top of piston below top face of crankcase. . . . . . . . . . . . . . . . . . . . . . . 0,310 to 0,380 mm (0.012 to 0.015 in)

(Machine top face of piston to obtain correct clearance)

Piston rings

Clearances of piston rings in grooves (A3)

Top ring CV 5907 (wedge shaped - new)  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Refer to ring gap dimensions

Second ring OE41689 (new) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0,0635 to 0,1016 mm (0.0025 to 0.0040 in)

Maximum permissible worn clearance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0,152 mm (0.006 in)

A

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Clearances of piston rings in grooves (continued)

Refer to the illustration (A) on page 72.

Third ring OE 42641 (new)  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0,0635 to 0,1143 mm (0.0025 to 0.0045 in)

Maximum permissible worn clearance  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0,152 mm (0.006 in)

Oil control ring CV 5908 (new)  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0,049 to 0,086 mm (0.0019 to 0.0034 in)

Maximum permissible worn clearance  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0,152 mm (0.006 in)

Free length of coil spring (new) . . . . . . . . . . . . . . . . . . . . . . . . . . . 423,96 to 426,34 mm (16.691 to 16.785 in)

Piston ring gaps measured with ring in new liner (A4)

Top ring CV 5907 (new)  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0,50 to 0,70 mm (0.0196 to 0.0275 in)

Maximum permissible worn gap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1,397 mm (0.055 in)

Second ring OE 41689 (new)  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0,432 to 0,686 mm (0.017 to 0.027 in)

Maximum permissible worn gap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1,524 mm (0.060 in)

Third ring OE 42641 (new)  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0,432 to 0,686 mm (0.017 to 0.027 in)

Maximum permissible worn gap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1,524 mm (0.060 in)

Oil control ring CV 5908 (new)  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0,430 to 0,810 mm (0.0169 to 0.0319 in)

Maximum permissible worn gap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1,016 mm (0.040 in)

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Pistons - 3 rings

Gudgeon pin in piston (A1)

(Gudgeon pin to be push fit at 20°C)

Bore in piston (new). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54,999 to 55,009 mm (2.1653 to 2.1657 in)

Gudgeon pin diameter (new) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54,995 to 55,000 mm (2.1652 to 2.1654 in)

Gudgeon pin in piston - clearance (new) . . . . . . . . . . . . . . . . .-0,001 to +0,014 mm (-0.00004 to +0.00055 in)

Top groove in piston

(wedge shaped for top ring CV 19329)

Diameter over 3,666 mm (0.1443 in) dia. rollers . . . . . . . . . . . . 135,155 to 135,405 mm (5.3211 to 5.3309 in)

Piston clearance at TDC (A2)

Top of piston below top face of crankcase. . . . . . . . . . . . . . . . . . . . . . . 0,310 to 0,380 mm (0.012 to 0.015 in)

(Machine top face of piston to obtain correct clearance)

Piston rings

Clearances of piston rings in grooves (A3)

Top ring CV 19329 (wedge shaped) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Refer to ring gap dimensions

Second ring CV 18638 (new). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0,067 to 0,090 mm (0.0026 to 0.0035 in)

Maximum permissible worn clearance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0,152 mm (0.006 in)

A

127

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Clearances of piston rings in grooves (continued)

Refer to the illustration (A) on page 74.

Oil control ring CV 18639 (new)  . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0,048 to 0,085 mm (0.0019 to 0.0034 in)

Maximum permissible worn clearance  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0,152 mm (0.006 in)

Free length of coil spring (new) . . . . . . . . . . . . . . . . . . . . . . . . . . . 423,96 to 426,34 mm (16.691 to 16.785 in)

Piston ring gaps measured with ring in new liner (A4)

Top ring CV 18637 (wedge shaped - new) . . . . . . . . . . . . . . . . . . . . . .  0,35 to 0,55 mm (0.0138 to 0.0217 in)

Maximum permissible worn gap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1,397 mm (0.055 in)

Second ring CV 18638 (new)  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0,43 to 0,68 mm (0.017 to 0.027 in)

Maximum permissible worn gap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1,524 mm (0.060 in)

Oil control ring CV 18639 (new)  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0,40 to 0,78 mm (0.016 to 0.031 in)

Maximum permissible worn gap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1,016 mm (0.040 in)

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Connecting rods

Gudgeon pin in bush (A1)

Bore of bush. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55,035 to 55,050 mm (2.1667 to 2.1673 in)

(Bush pressed into position and bored to size)

Diameter of gudgeon pin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54,995 to 55,000 mm (2.1652 to 2.1653 in)

Clearance (new). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0,035 to 0,055 mm (0.0014 to 0.0022 in)

Permissible worn clearance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0,067 mm (0.0026 in)

Bush in small end (A2)

Bore in connecting rod. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60,00 to 60,03 mm (2.3622 to 2.3633 in)

Diameter of bush . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60,072 to 60,097 mm (2.365 to 2.366 in)

Interference fit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0,042 to 0,097 mm (0.0017 to 0.0038 in)

Alignment of connecting rod (A3)

Parallel alignment  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0,025 mm (0.001 in)

(Measured between big end and small end, for each 25,40 mm (1.000 in) of test mandrel)

Distance between centres . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 273,05 to 272,95 mm (10.750 to 10.746 in)

End-float of big end (A4)

End-float. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0,20 to 0,40 mm (0.008 to 0.016 in)

Permissible worn end-float. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0,558 mm (0.022 in)

(End-float of each set of two big ends on common crank pin)

Clearance on diameter of big end (A5)

Clearance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0,026 to 0,086 mm (0.001 to 0.003 in)

(Check that crank pin is within limits of ovality)

A

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Holes are drilled through the diameter of the main

journals.  The holes are connected with holes in each

crank pin to supply lubricating oil to the big end

bearings of the connecting rods.  The seventh main

journal at the rear of the crankshaft is not drilled.

Crankshaft assembly

14

For engines built up to build number 970208 the holes

are connected through each crankshaft web to the

reservoirs in the crank pins (A2).  The oil flows to the

bearing surfaces of the crank pins from the reservoirs

through two holes (A6) which are drilled in each crank

pin.

General description

The crankshaft is made from a forging of chromium

molybdenum steel.  It is nitrided on all surfaces except

the tapped holes, the hole for the dowel and the end

faces at the front and the rear.  The correct balance is

obtained when the crankshaft is machined, and there

is no requirement for further compensation when

assembled.

The small holes in the crankshaft webs are sealed

with special blanking plugs (A5).

The crank pin arrangement is 1 and 6, 2 and 5, 3 and

4.  Each set of two crank pins is aligned 120 degrees

from the other two sets.  This gives a firing order of

A6, B1, A3, B4, A5, B2, A1, B6, A4, B3, A2 and B5.

The 13 bearing surfaces consist of seven main

journals and six crank pins.  Each crank pin holds two

connecting rods.

A helical gear (A4) with 45 teeth is machined around

the rear end of the crankshaft and is the primary drive

for the timing gears.  The face at the rear of the

crankshaft has 16 equally spaced tapped holes to

receive the cap screws which retain the flywheel.  A

dowel of the spring type is fitted in a hole in the face

to ensure an accurate alignment of the timing mark on

the flywheel.

The crankshafts of engines manufactured up to build

number 970209 have an oil reservoir in each crank

pin.  Access to clean each reservoir is provided by a

steel plug (A8) which is retained by a spring clip (A9).

The crankshafts of engines from build number

970209 have an arrangement of passages which

removes the requirement for oil reservoirs.

A

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A helical gear (A1) with 45 teeth is machined around    Crankshaft pulley, damper and

the front end of the crankshaft.  The gear drives the

lubricating oil pump through an idler gear. The face at

the front end is drilled and tapped for 12 equally

spaced bolts, which retain the viscous damper and

the multiple groove pulley for the fan drive belts.

alternator pulley

To remove and to fit

14-1

The main bearings have steel backs with bearing

surfaces of lead bronze.  The bearing surfaces have

a fine top layer of lead indium.

To remove

1  Release the large lock nut on the tensioner of the

fan belts and turn the adjustment screw to loosen the

fan belts.  Remove the fan belts.

The upper half of each bearing has a central groove

for oil around the inner surface.  A hole is drilled in the

centre of the groove and is aligned with a hole in the

crankcase which supplies the oil.

2  Remove two horizontally opposite bolts from the

crankshaft pulley.  Make locally two suitable guide

studs and fit them into the bolt holes.

The lower halves of the bearings do not have

grooves.

3  Remove the remainder of the twelve bolts from the

crankshaft pulley.  Lift away the pulley for the fan

belts, followed by the damper and then the alternator

pulley from the guide studs.

One end of each half bearing has a location tag which

is pressed away from one edge.  The tags fit in

recesses which are machined in the crankcase and in

the bearing caps.

Caution:  The damper is a heavy component and

must not be allowed to fall during removal, because

distortion of the casing can prevent its correct

operation.

The thrust washers have steel backs with faces of

lead bronze.  They are made in two halves which are

interchangeable.  Each half has a location tag at one

end.  The upper halves are fitted in recesses which

are machined in the crankcase on each side of the

central main journal; the lower halves are fitted in

recesses which are machined in the bearing cap.

To fit

1  Fit the guide studs into the horizontally opposite

bolt holes in the end face at the front of the crankshaft. 

Fit the alternator pulley on the guide studs, followed

by the damper and then the pulley for the fan belts.

Lubricating oil is supplied from the central main

bearing across the face of each washer, in which

grooves are machined to assist the flow of oil.

2  Insert ten bolts, with their spring washers, through

the bolt holes and tighten securely the assembly to

the crankshaft.  Remove the guide studs and fit the

two remaining bolts and their spring washers.

3  Tighten each bolt to 80 Nm (59 lbf ft).

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Front oil seal

To renew

14-2

Special tools:

Remover/replacer, 21825 905

To remove

1  Remove the crankshaft pulley, the damper and the

alternator pulley, operation 14-1.

2  Use the kit of the remover/replacer, 21825 905, to

remove and to replace the oil seal.  Use the two short

setscrews in the kit to fit the top plate (A4) to the front

end of the crankshaft.  Ensure that the counterbores

of the holes around the edge of the top plate are away

from the engine.

3  Use the centre punch in the kit, through the holes

around the edge, to either make three holes in the oil

seal, or to mark the centres in order to drill three holes

of a size which is suitable to receive the three 40 mm

(1.5 in) long self-tapping screws in the kit.’

Caution:  Three holes around the edge of the top

plate are marked ’A’ and three holes are marked ’B’. 

Use the relevant group of holes which align centrally

with the metal of the seal.

A

129

4  Fit the three self-tapping screws through the holes

in the top plate into the holes in the seal.  Do not

overtighten.  Remove the setscrews which retain the

top plate and fit the three long screws of the kit. 

Tighten evenly the screws against the end of the

crankshaft to pull out the seal.  Remove the self-

tapping screws when the seal is withdrawn.

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To fit

46

1  Ensure that the crankshaft, the fan adaptor and the

oil seal are clean.  Use the kit of the remover/replacer,

21825 905, to fit the new oil seal at the front end of the

crankshaft.  Fit the four special studs (A2) into four

equally spaced bolt holes in the end face of the

crankshaft (A1). Tighten lightly each special stud and

hold the guide (A5) against the end face of the

crankshaft.

2  Insert the four cap screws (A3), through the four

small holes in the guide, into the special studs. DO

NOT tighten the cap screws.

3  Slide the collar (A6) over the guide and the

crankshaft to ensure the concentricity of the guide on

the crankshaft.  Tighten the four cap screws and

remove the collar.

4  Before the new oil seal (A7) is fitted, check the

guide and the crankshaft for dirt or a rough surface

finish which could damage the lip of the oil seal.

5  Apply a small amount of clean engine lubricating oil

to the guide and the flange of the crankshaft, remove

and discard the yellow inner sleeve, and slide the seal

onto the parallel section of the guide. The lip of the

seal is toward the crankcase.

6  Slide the collar onto the guide until the face of the

collar presses against the outer face of the oil seal.

A

Caution:  This tool is used for both CV8/3008 and

CV12/3012 engines and the collar is marked to show

the correct assembly for each engine.  It is important

that the collar is fitted correctly.  For CV12/3012

engines, the edge of the shorter of the two shoulders

which are machined on the collar must be against the

oil seal.

129

7  Fit the top plate (A4) onto the central stud and

engage its shoulder in the collar.  Lightly lubricate the

thread of the stud and also the thrust washer. Fit the

nut and the thrust washer to retain the top plate.  Use

the correct spanner to tighten the nut until the larger

diameter of the collar is in contact with the face of the

housing.  Remove the complete tool.

8  Fit the crankshaft pulley, the damper and the

alternator pulley, operation 14-1.

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Rear oil seal

To renew

14-3

Special tools:

Remover/replacer, 21825 810

To remove

1  Remove the flywheel, operation 22-1.

2  Use the kit of the remover/replacer, 21825 810, to

remove and to replace the oil seal.  Use the two short

setscrews in the kit to fit the top plate (A4) to the rear

end of the crankshaft.  Ensure that the counterbores

of the holes around the edge of the top plate are away

from the engine.

3  Use the centre punch in the kit, through the holes

around the edge, to either make three holes in the oil

seal, or to mark the centres in order to drill three holes

of a size which is suitable to receive the three self-

tapping screws in the kit.

Caution:  Three holes around the edge of the top

plate are marked ’A’ and three holes are marked ’B’. 

Use the relevant group of holes which align centrally

with the metal of the seal.

A

129

4  Fit the three self-tapping screws through the holes

in the top plate into the holes in the seal.  Do not

overtighten.

5  Remove the setscrews which retain the top plate

and fit the three long screws of the kit. Tighten evenly

the screws against the end of the crankshaft to pull

out the seal.  Remove the self-tapping screws when

the seal is withdrawn.

To fit

1  Ensure that the crankshaft, the flywheel housing

and the oil seal are clean.  Use the kit of the remover/

replacer, 21825 810, to fit the new oil seal at the rear

end of the crankshaft as follows:

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2  Fit the dowel, which provides the location for the

flywheel, into its hole in the end face of the crankshaft

and align the guide (A5) for the seal, to ensure that

the dowel enters a hole in the guide. The hole is a

clearance fit on the dowel.  Make a temporary mark

on the flange of the crankshaft to show the alignment 

of the three bolt holes in the guide.

3  Lift away the guide and fit the three special studs

(A2) of the kit into the three relevant bolt holes in the

end face of the crankshaft (A1). Tighten lightly each

special stud, engage correctly the dowel in the hole

and hold the guide against the end face of the

crankshaft.

4  Insert the three cap screws (A3) of the kit through

the guide into the special studs and tighten lightly the

cap screws.

5  Before the oil seal (A7) is fitted, check again the

guide and the crankshaft for dirt or for a rough surface

finish which could damage the lip of the oil seal.

6  Apply a small amount of clean engine lubricating oil

to the guide and the flange of the crankshaft, remove

and discard the yellow inner sleeve, and fit the seal

onto the guide.  The lip of the seal is toward the

crankcase. 

7  Slide the collar (A6) onto the guide until the face of

the collar presses against the outer face of the oil

seal.

A

129

Caution:  This tool is used for both CV8/3008 and

CV12/3012 engines and the collar is marked to show

the correct assembly for each engine.  It is important

that the collar is fitted correctly.  For CV12/3012

engines, the edge of the shorter of the two shoulders

which are machined on the collar must be against the

oil seal.

8  Fit the top plate (A4) onto the central stud and

engage its shoulder in the collar.  Lightly lubricate the

thread of the stud and also the thrust washer. Fit the

nut and the thrust washer to retain the top plate.  Use

the correct spanner to tighten the nut until the larger

diameter of the collar is in contact with the face of the

housing.  Remove the complete tool.

9  Fit the flywheel, operation 22-1.

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Crankshaft

To remove and to fit

14-4

Special tools:

Lift adaptor, crankshaft VP 666

Slide hammer, 21825 849

Remover tool, 21825 858

Guide pin, 21825 843

To remove

1  Fit the engine in the build stand, operation 16-1.

2  Remove the fan adaptor and the front mountings,

operation 21-10.

3  Remove the flywheel and the flywheel housing,

operation 22-4.

4  Remove the timing case and the timing gears,

operation 15-5.

5  Remove the lubricating oil sump, operation 19-1 or,

for new engines, operation 19-5.

6  For early engines, remove the sump adaptor,

operation 19-3.

7  Remove the lubricating oil pump, operation 19-7.

8  Turn the crankshaft until one of the pistons of ’A’

bank is at the bottom of its stroke and remove the four

nuts of the big end bearing.  Withdraw the bearing cap

with the bearing.  Fit the guide pin, 21825 843, on to

one of the bolts of the big end.

9  Push the assembly of the piston and the connecting

rod into its bore to the end of its stroke. Push carefully

to prevent damage to the top of the piston and the

valves.

10  Similarly, repeat the operation for the remainder of

the assemblies.  Move the guide pin as necessary.

11  Turn the crankcase for access to the big end

bearings of ’B’ bank.  Repeat the operation for the

assemblies of pistons and connecting rods, as for ’A’

bank.Loosen all the bolts that retain the main bearing

caps.  Release and remove the side bolts.

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12  Remove the bolts from each main bearing cap and

remove the caps.  If necessary use the slide hammer,

21825 849, with the remover tool, 21825 858, to

withdraw each main bearing cap (A3,4,5,9) and its

lower half bearing (A1,8).  When the central main

bearing cap (A3) is removed, remove also the lower

halves of the thrust washers (A10).

13  Slide the upper halves of the thrust washers (A6)

from their recesses around the central main journal. 

Use the lift adaptor VP 666 to lift the crankshaft from

the crankcase and put it on wooden vee blocks. 

Remove the upper halves of the main bearings (A2,7)

from the crankcase and also the upper halves of the

thrust washers.

To fit

1  Check for dirt and debris in the passages for the

engine lubricating oil of the crankcase, and also of the

front and the rear main bearing caps (A5,9). Clean

thoroughly the bearing housings and the bearing

caps, and also the main journals and the crank pins of

the crankshaft.

2  Check also for dirt and debris in the passages of the

connecting rods and clean thoroughly the bearing

surfaces of the big ends.

3  Ensure that the half bearings and the thrust

washers for the main journals of the crankshaft are

absolutely clean, and fit the upper half bearings into

their housings in the crankcase.  Give a full

application of clean engine lubricating oil to all of the

bearing surfaces.

A

206

4  Also, apply clean engine lubricating oil to lubricate

fully the main journals of the crankshaft. Use the lifting

beam VP 666 to lower the crankshaft into the

crankcase (B).  Ensure that the 16 tapped holes in the

end face of the crankshaft are furthest from the build

stand, and are at the end of the crankcase to which

the timing case is fitted.

5  Apply engine lubricating oil to the upper halves of

the thrust washers and insert them into their recesses

on each side of the central main bearing. Ensure that

the face of lead bronze on each washer is toward the

crankshaft web.

B

201

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6  Fit the lower halves of the main bearings into the

bearing caps and give a full application of clean

engine lubricating oil to all of the bearing surfaces. Fit

all the assemblies of the bearing caps except the

bearing cap for the central main bearing. Ensure that

the numbers which are stamped on each bearing cap,

to give its relationship, match the numbers which are

stamped on the crankcase, as shown (A).

7  Apply a minimum amount of grease to the recesses

at the sides of the bearing cap for the central main

bearing and insert the lower halves of the thrust

washers into the recesses.  Ensure that the face of

lead bronze on each washer is away from the bearing

cap.

8  Fit carefully the assembly of the bearing cap for the

central main bearing.  Ensure that the halves of the

thrust washers remain in their positions during the

operation.

9  Apply engine lubricating oil to the threads, and

under the heads, of the main bolts which retain the

main bearing caps.  Fit carefully each bolt into its

location.  Do NOT allow the bolts to fall into the holes

because the threads could be damaged. Insert fully

each main bolt by hand only.

Caution:  On new engines, the bolts fitted to the front,

centre and rear bearing caps, are different and are

fitted with hardened washers.  Ensure that the special

washers are fitted to the bolts before the bolts are

fitted to the engine.  Do NOT fit any other type of

washer.

A

203

Caution:  If a new front, centre or rear bearing cap is

fitted, do NOT fit the old type of bolts.  The new bolts

and special washers MUST be used.

10  Apply engine lubricating oil to the threads, and

under the heads, of the side bolts which hold rigidly

the main bearing caps.  Fit the plain washers on the

M16 bolts and the ’Dowty’ sealing washers on the

M14 bolts.  Insert fully each bolt, by hand, through the

side walls of the crankcase.

11  Check that the faces which are machined on the

front and the rear of each main bearing cap are

aligned with the faces in the crankcase.  Tighten

lightly all of the main bolts and then all of the side

bolts.

B

202

12  Tighten, in the sequence shown in page 86/B, all

the main bolts of the bearing caps by increments of 50

Nm (37 lbf ft) until the maximum torque of 177 Nm

(130 lbf ft) is applied.  At the end of this phase of the

operation, the main bolts of the main bearing caps at

the front, at the centre and at the rear are tightened

fully.

Caution:  Check frequently that the crankshaft can

rotate freely while the bolts are tightened.

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13  Continue to tighten the bolts - numbers 5 to 12 (B)

- for the remainder of the main bearing caps, until the

maximum torque of 488 Nm (360 lbf ft) is applied.

14  Tighten all the side bolts, in alphabetical

sequence, until a maximum torque of 114 Nm (85 lbf

ft) is applied.  At the end of this phase of the operation,

the side bolts of the front, central and rear main

bearings are tightened fully.

15  Continue to tighten the remainder of the side bolts

- letters C to J (B) - in alphabetical sequence, until a

maximum torque of 177 Nm (130 lbf ft) is applied.

16  Put a dial test indicator with a magnetic base on

the end face of the crankcase.  Set the button of the

dial test indicator on the end of the crankshaft (A). 

Use a lever to move the crankshaft backward and

forward against the thrust washers and check the

readings on the dial test indicator.  Permissible end-

float is 0,10 to 0,30 mm (0.004 to 0.012 in).

Turn the crankcase in the build stand so that the ’A’

bank cylinders are horizontal.  Fit each of the

connecting rods, of the ’A’ bank cylinders, to their

respective crank pins, operation 13-3.

A

205

A

192

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17  When all of the ’A’ bank connecting rods have

been fitted, turn the build stand until the ’B’ bank

cylinders are horizontal and use the same procedure

to fit the connecting rods of the ’B’ bank.

18  Set a dial test indicator as shown (page 67/B) and

check the end float of each big end.  The permissible

end float is 0,2 to 0,4 mm (0.008 to 0.016 in).

19  Ensure that the crankshaft turns freely.

20  Fit the lubricating oil pump, operation 19-7.

21  For early engines, fit the sump adaptor, operation

19-3.

22  Fit the lubricating oil sump, operation 19-1 or, for

new engines, operation 19-5.

23  Fit the timing case and the timing gears, operation

15-5.

24  Fit the flywheel and the flywheel housing,

operation 22-4.

25  Fit the fan adaptor, operation 21-10.

26  Remove the engine from the build stand,

operation 16-1.

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To dismantle and to assemble

14-5

Special tools:

Lift adaptor, crankshaft VP 666

Remover/replacer, 27610005

To dismantle

1  Press down each plug (A1) of the reservoirs and

release the circlips.  Fit the remover/replacer,

27610005 (A2), on the spigot of the plug and withdraw

the plug.    Early engines are fitted with a different type

of plug which has a threaded hole, for these engines

use remove/replacer, 21825 859, together with the

slide hammer, 21825 849.  Clean all the components

with a degreasing solution.

A

01

4  Check for damage on the front and rear faces at the

ends of the crankshaft.  Also check for small marks on

the circumferences which are the location faces for

the flywheel and the pulley.

To assemble

5  If the crankshaft is usable, small marks can be

removed from the journals, the crank pins, the thrust

faces and the locations on the ends by the use of a

very fine grade of oil stone.

1  Fit new ’O’ ring seals to the blanking plugs of the

reservoirs.  In sequence, apply a small amount of

’Stantyte’ lubricant or ’Morris’s liner lubricant’ around

the complete circumference of each housing in the

crankshaft.  Press fully each plug into its housing and

fit the circlip into its recess in the housing.  Use the

relevant remover/replacer to pull backward the plug

against the circlip.

Main bearings and thrust washers

To inspect

14-6

14-7

To clean and inspect

1  Remove the crankshaft, operation 14-4.

To clean

2  Check for wear, cracks and contamination in the

surfaces of the bearings.  Renew bearings as a set if

it is possible that a bearing will not complete a further

full period of service.

1  Wash thoroughly the oil holes and reservoirs of the

crankshaft with kerosene and dry with compressed

air.  Ensure that all surfaces of the crankshaft are

cleaned thoroughly.

3  Check the thickness of the thrust washers.

Nominal dimensions for new thrust washers are:

To inspect

2,93 to 3,0 mm (0.116 to 0.118 inch)

1  Hold the shaft in suitable wooden blocks under

main journals nos. 1 and 7.  Check  for cracks in the

crankshaft, by the electro-magnetic method if

possible.

New thrust washers must be fitted if there is wear on

the thrust faces and also if the crankshaft has

excessive end-float.

2  Check for damage and small marks on the main

journals, crank pins and thrust faces; check for ovality

the journals and crank pins.  Refer to Perkins Engines

Company Limited, Shrewsbury, for the instructions

S.R.S. 121 Issue 2 for the repair of worn or damaged

journals and crank pins.

3  Hold the crankshaft in ’V’ blocks under the main

journals nos. 1 and 7 and check the amount of

deflection at the central main journal.  The permissible

amount of the deflection, which is given on page 89,

must be gradual along the length of the crankshaft.

88

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Width of central bearing (A4) across thrust washers

Fits and clearances

81,15 to 81,30 mm (3.1949 to 3.2008 in)

Crankshaft journals

Clearance (new)0,13 to 0,33 mm (0.005 to 0.013 in)

Permissible worn clearance0,483 mm (0.019 in)

Diameter (A1)145,975 to 146,000 mm (5.7470 to

5.7480 in)

Flywheel on crankshaft

Permissible worn dimensions145,910 mm (5.7445 in)

Ovality - permissible worn dimensions0,076 mm

(0.0030 in)

Journals in main bearings – clearance0,076 to 0,145

mm (0.0030 to 0.0057 in)

Bore of flywheel160,000 to 160,025 mm (6.2992 to

6.3002 in)

Diameter of  crankshaft (A5)159,961 to 159,986 mm

(6.2976 to 6.2986 in)

Clearance (new)0,014 to 0,064 (0.0006 to 0.0026)

Crank pins

Diameter (A2)97,978 to 98,000 mm (3.8574 to 3.8583

in)

Diameter - permissible worn dimensions97,914 mm

(3.8548 in)

Ovality - permissible worn dimensions0,076 mm

(0.0030 in)

Deflection of crankshaft

Deflection of crankshaft (A6) when it is held in

'V' blocks under nos. 1 and 7 main journals0,1000 mm

(0.0039 in)

(Deflection must be gradual from outer main journals

to central main journal)

End float of crankshaft

Width between crankshaft webs of central journal

(A3)81,43 to 81,48 mm (3.2059 to 3.2079 in)

A

131

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Timing gears and timing case

15

General description

The timing gears (A) of the engine are protected by a

housing at the rear of the engine which has two

components, the timing case and the flywheel

housing.

The timing case is made from heavy-duty cast iron

and is bolted to the rear end of the crankcase.  It has

mountings for the connection block for the spill fuel,

the starter motor and the coolant pump.  It holds the

inner bearing, and the housing for the oil seal, of the

auxiliary drive shaft.

For early engines, the oil seal of the auxiliary drive

shaft is separate and is pressed into its housing. The

current engine has a housing with an integral oil seal. 

The housing also has an ’O’ ring in a groove around

its spigot to seal the bore in the timing case.

The flywheel housing is also made from heavy-duty

cast iron and is bolted to the timing case.  It holds the

outer bearing for the end of the auxiliary drive shaft

and has a mounting for the fuel lift pump. The correct

location of the assembly is ensured by a large dowel

and the axles of the idler gears in the timing case.

The arrangement of the timing gears consists of the

drive gear on the crankshaft (A6), the idler gear (A7)

for the drive to the gear of the coolant pump (A8), the

double idler gear (A4,5), the main idler gear (A9), the

drive gear for the fuel injection pump/camshafts (A1),

the two camshaft gears (A3) and the auxiliary drive

gear (A2).  The drive gear for the fuel injection pump/

camshafts is bolted to the outer face of the camshaft

gear of ’B’ bank.

A

132

The axles of the idler gears are bolted to the rear end

of the crankcase and the end float of each gear is

limited by the thrust washers.

There are timing marks on the drive gear of the

crankshaft, the double idler gear, the main idler gear,

the drive gear for the fuel injection pump/camshafts,

the two camshaft gears and the auxiliary drive gear. 

The use of the timing marks ensures that the mesh of

each gear is correct, before the timing of the fuel

injection pump is checked and before the tappet

clearances are set. The teeth of the timing gears are

engaged correctly when the mark on the side of the

tooth of a gear is between the marks on the sides of

two teeth of another gear (A).

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