125000950 - 1028H14 PISTON CONNECTING ROD SET - R R

Removing ( Refitting ) 1. Undo the plug and drain the engine oil.
Collect the engine oil in a suitable container.
Rotate the engine through 180° on the overhaul stand.1. Undo the front and rear bolts (1a) fixing the crankcase sump using the tool (1b).
DescriptionCode
1bSpanner1.860.833.001
2. Undo the side bolts (2a) fixing the crankcase sump using the tool (2b).
DescriptionCode
2bSpanner1.860.834.001
3. Cut the crankcase sump sealant using the tool.
DescriptionCode
3Blade1.870.718.000
4. Remove the crankcase sump.
Turn the crankshaft by adjusting the bolt of the toothed drive pulley until the pistons of the 1st and 4th cylinder are set to BDC.1. Undo the bolts (1a) and remove the connecting rod caps (1b) complete with half-bearings (1c) for cylinders 1 and 4.2. Remove the cylinder 1 and 4 piston-connecting rod assemblies (2a) complete with half-bearings (2b)Carry out the same operations to remove the connecting rod half-bearings for the remaining cylinders.
Refitting ( Removing )
This engine is fitted with main bearing and connecting rod bearing halves specially selected to achieve an optimised, instant mating clearance.
The crankshaft supplied by the Parts Dept. comes without half-bearings and the main journals and crankpins are the "normal" size; the half-bearings to be fitted must therefore be selected identifying the class of each main journal and crankpin for the new crankshaft.

The following must be determined for the selection of crankpin half-bearings:

  • The numerical code stamped on the phonic wheel;
  • the paint mark (if present) added in a position adjacent to the crankpins.
Below is an example of the identification of crankpin grades:
1 - Crankpin identification numerical code: the left hand number refers to the first timing side pin; the final "N" is a non-essential code for 4 cylinder engines.2 - Main journal identification numerical code: the left hand number refers to the first timing side journal; the final "N" is a non-essential code for 4 cylinder engines.3 - Series of numbers (if present), in groups of two digits, which indicate the dimensions (thousandth part) of the main journals: the first two numbers on the left refer to the first timing side journal.
Only use the codes that relate to the key, all other codes on the flywheel should not be used.
For the identification of the crankpin grade, refer to the numerical code for key reference 1.In the case of the example, the numbers 2222N indicate that all six bearings are Grade B (blue) as indicated below.CRANKPIN IDENTIFICATIONCategory of crankpin A (normal), diameter 50.787 50.793 mm, RED paint spot, numerical code 1 (87 93)*Category of crankpin B (normal), diameter 50.793 50.799 mm, BLUE paint spot, numerical code 2 (93 99)*Category of crankpin C (normal), diameter 50.799 50.805 mm, YELLOW paint spot, numerical code 3 (99 05)*Category of crankpin D (undersized by 0.127 mm, diameter 50.660 50.666 mm, BROWN paint spot, numerical code 6 (60 66)*Category of crankpin E (undersized by 0.127 mm, diameter 50.666 50.672 mm, GREEN paint spot, numerical code 7 (66 72)*Category of crankpin F (undersized by 0.127 mm, diameter 50.672 50.678 mm, BLACK paint spot, numerical code 8 (72 78)*(*): Last two numbers (thousandth part) of the main journal dimensionsIn the case of the usage of a crankshaft where the maximum undersize for the bearings is 0.127 mm through grindings, the grade should be selected through the measurement of the diameter of the pin with reference to the above.Having defined the grade and the colour of each new or reground crankpin, it is necessary to select the thickness of the bearings that should be the same colour as the corresponding bearing; the pair of half-bearings required can be ordered from the Parts Dept. by quoting the order no.The above is designed to guarantee the optimum operational clearances for all the pins.In general, the clearance between the crankpin and half-bearing, obtained by the selection method described above, should be 0.030 0 0.056 mm. As a final check, this value may be measured using plastic gauge as described below.1. Refit the piston-connecting rod assemblies (1a) with half-bearings (1b) selected as described previously.
The piston-connecting rod assemblies should be fitted so that the arrows stamped on the piston crown are facing the exhaust side.
Rotate the crankshaft so that the crankpins are accessible.1. Fit the calibrated wire (plastigage) for measuring the crankpin clearance.
1. Place the bearing cap (1a), complete with half-bearing, back in its housing and secure it tightening the nuts (1b) to the recommended torque.
The references on the connecting rod cap and the big end should be on the same side.
FasteningComponentØ  Value(daNm)
1bBoltCONNECTING ROD CAPSM92.4 ÷ 2.6 +60?
2. Use the tool for the angular tightening of the connecting rod cap bolts.
DescriptionCode
2Torque wrench1.860.942.000
1. Remove the bearing cap fitted previously and, using a suitable graduated measuring instrument (1a), measure the clearance shown by the compression of the calibrated wire (1b).
arry out the clearance measurement operation for all the pins, taking care to proceed one pin at a time.
MeasurementValue
-Crankpin/half-bearnig clearance (mm)0.030 ÷ 0.056
If the figure measured is outside of the tolerance, replace the connecting rod half-bearings with ones of the appropriate size and category.
1. Place the connecting rod caps (1a) complete with half-bearings in their housings and secure them tightening the bolts (1b) to the recommended torque.
The references on the connecting rod cap and the big end should be on the same side.
FasteningComponentØ  Value(daNm)
1bBoltCONNECTING ROD CAPSM92.4 ÷ 2.6 +60?
2. Use the tool for the angular tightening of the connecting rod cap bolts.
DescriptionCode
2Torque wrench1.860.942.000
Clean any sealant residues from the mating surfaces between the engine oil sump and the engine block.Apply silicon sealant to the entire perimeter of the crankcase sump.1. Position the sump on the crankcase.2. Tighten the front and rear bolts (2a) fixing the crankcase sump to the recommended torque using the tool (2b).
FasteningComponentØ  Value(daNm)
2aFront and rear boltsOIL SUMPM6(Engine crankcase side) 0.8 - 1.0
DescriptionCode
2bSpanner1.860.833.001
3. Tighten the side bolts (3a) fixing the crankcase sump to the recommended torque using the tool (3b).
FasteningComponentØ  Value(daNm)
3aSide boltsOIL SUMPM8(Engine crankcase side) 2.3 - 2.8
DescriptionCode
3bSpanner1.860.834.001
Tighten the engine oil drain plug to the recommended torque.
FasteningComponentØ  Value(daNm)
--ENGINE OIL DRAIN PLUGM18(Crankcase sump side) 1.8 - 2.2