- Remove the crankshaft
position sensor. Inspect the position sensor for damage. Replace the sensor
if necessary.
- Remove the main bearing bolts.
- Remove the bearing caps.
Notice: Remove the crankshaft carefully in order to avoid damaging the crankshaft
journals, the rod, the main bearing inserts, or the connecting rods.
- Remove the crankshaft from the block.
- Remove the bearing inserts from the block.
- Clean the oil, sludge, and carbon.
- Inspect the oil passages for obstructions.
- Inspect the keyway.
- Inspect the threads.
- Inspect the bearing journals and the thrust surfaces for the following
conditions:
| • | Overheating (discoloration) |
- Inspect the corresponding bearing inserts for imbedded foreign
material. If foreign material exists, find the cause and repair the cause.
Important: Replace the crankshaft if cracks, severe gouges, or burned spots are
found. Slight roughness may be removed with a fine polishing cloth soaked
in clean engine oil. Burrs may be removed with a fine oil stone.
- Measure the crankshaft journals. Use a micrometer or dial indicator
to measure the taper and runout. Note the result for the later selection of
bearing inserts. If not within limits the crankshaft must be replaced.
Note the location of the main bearing high spots. If they are not in
line, the crankshaft is bent and must be replaced.
