Crankshaft Main Bearing: Service and Repair

NOTE: This operation should only be carried out if crankshaft damage is not suspected and the problem is due to bearing shell wear or failure. If, upon inspection, journals are found to be damaged, the engine must be removed and the crankshaft renewed.


To complete this operation in the car, it will be necessary to remove the front suspension unit. Refer to Steering and Suspension/Suspension/Service and Repair
- Raise the vehicle on a ramp.
- Remove front suspension unit.
- Remove the sump plug and drain the oil into a suitable container.

Oil Pan Bolts:

- Remove the sump pan securing bolts (2) and remove the sump pan (1).

Fig. 10 Suction Elbow And Sandwich Plate Removal:

- Remove the suction elbow (2), remove the sandwich plate securing bolts (1) and remove the plate, noting the different stud lengths.

Oil Pickup Pipe:

- Remove the suction pipe securing bolts (3) and disconnect the suction pipe (2) from the elbow.
- Remove the delivery pipe/undershield securing bolts, and draw the undershield clear.
- Remove the bolt, washer and nut securing the delivery pipe elbow to the oil pump casing.

NOTE: Leave the bolt at the outboard fastening in position in the oil pump casing. If the bolt is removed for any reason, it must be refitted from a downward direction.

- Draw the delivery pipe elbow downwards from the bore in the crankcase and the oil pump casing. Remove and discard the gasket.
- Draw the undershield clear.

CAUTION: Do not rotate the crankshaft while the bearing caps are disconnected.

NOTE: The center and rear bearing shells cannot be interchanged; the rear main bearing shell has an oil groove, the center main bearing shell is of plain construction.
The rear main bearing is secured with four small nuts/washers and two large nuts/washers.

Main Bearing Cap:

- Remove the one (front) main bearing cap securing nuts (2) and remove the cap (3).
- Remove and discard the bearing shell (4).
- Carefully remove the shell from behind the main bearing journal (5), taking care not to mark the journal face. Discard the shell.
- Clean all components and bearing surfaces.
- Coat one new shell half with clean engine oil. Carefully fit the shell behind the main bearing journal.
- Coat the bearing surface with clean engine oil. Fit the shell to the cap.
- Fit the cap the crankshaft.
- Fit and torque tighten the securing nuts.
- Repeat the shell replacement procedure for the remaining main bearings.
- Refit the delivery pipe elbow, using a new O-ring.
- Refit the delivery pipe and undershield.
- Refit the suction pipe, using a new O-ring.
- Clean the oil strainer.
- Refit the sandwich plate assembly.
- Refit the sump.
- Refit front suspension unit.
- Refit the drain plug, using a new washer and refill the engine with clean oil.

TORQUE FIGURES
Main bearing cap nuts (1/2") 84 Nm maximum
Main bearing cap nuts (3/8") 36.5-38Nm
Oil cooler pipes 54-6O Nm
Sandwich plate to block 16.5-21 Nm
Sump drain plug 15-18 Nm
Sump set screws 16-2O Nm