(5) Inspect rear end of crankshaft at area
of oil seal contact surface for
evidence of rough or grooved
condition. Slight ridges on crankshaft
oil seal contact surface may be
cleaned up with crocus cloth. If
crankshaft cannot be cleaned up
satisfactorily, reposition oil seal in
(6) Check crankshaft thrust surfaces for
excessive wear or grooving. If only
slightly worn, surfaces may be
dressed with an oil stone.
Minute cracks can be detected by using Magnetic Particle Inspection Method.
Crankshaft failures are rare and when one cracks or breaks completely, it is very
important to make a thorough inspection for contributory factors.
Inspect crankshaft for fatigue cracks
which start at an oil hole and follow
journal surface at an angle of 45
degrees to axis. Reject crankshaft
Inspect main bearing shells for bright
spots on backs indicating movement
in bearing caps or supports. Discard
shells if this condition is present.
Install all upper and lower bearing shells as a set. Do not replace one main bearing
shell alone. When new crankshaft is used, install all new bearing shells.