Attention: Before removing the crankshaft, the following must be removed: flywheel, oil sump, oil pump, pistons with connecting rods and rear oil seal housing.
Before removing the crankshaft, check the end play of the shaft. Install the gauge with the indicator coaxially with the shaft and rest the gauge rod against the end face.
Press the shaft all the way back and set the indicator to zero. Then press the shaft all the way forward and record the arrow reading, which is equal to the backlash. If the play is greater than the allowable value, check the wear of the thrust surfaces of the shaft. If no wear is found, the clearance can be reduced by installing new main bearings.
Backlash can also be measured using feeler plates. Press the shaft all the way forward. Insert feeler gauges between the shaft and the front surface of the main bearing. Check if there is a marking on the main bearings. They must be numbered sequentially from the front of the engine to the rear. If there are no marks, mark with a center punch.
Often there is an arrow on the lids that points forward. If not, draw an arrow with a marker before removing the covers. Loosen the cover bolts in ¼ turn increments until they can be removed by hand.
Tap the covers gently with a soft-faced hammer, then remove them from the cylinder block. If necessary, use the bolts as levers to remove the covers. Try not to drop the bearing shells.
Carefully pull the crankshaft out of the engine. Put the bearing shells in place, install the bearing caps and tighten the bolts by hand.