6A – 94 ENGINE MECHANICAL
CRANKSHAFT AND BEARING
Inspect the surface of the crankshaft journals and
crankpins for excessive wear and damage.
Inspect the oil seal fitting surfaces for excessive wear and
damage.
Inspect the oil ports for obstructions.
Note:
To increase crankshaft strength, tufftriding (Nitrizing
Treatment) has been applied. Because of this, it is not
possible to regrind the crankshaft surfaces.
Therefore, under size bearing are not available.
Crankshaft Tufftriding Inspection
1. Use an organic cleaner to thoroughly clean the
crankshaft. There must be no traces of oil on the
surfaces to be inspected.
2. Prepare a 5 – 10% solution of ammonium cuprous
chloride (dissolved in distilled water).
3. Use a syringe to apply the solution to the surface to be
inspected.
Hold the surface to be inspected perfectly horizontal to
prevent the solution from running.
Note:
Do not allow the solution to come in contact with the
oil ports and their surrounding area.
Judgment
1. Wait for thirty to forty seconds.
If there is no discoloration after thirty or forty seconds,
the crankshaft is usable.
If discoloration appears (the surface being tested will
become the color of copper), the crankshaft must be
replaced.
2. Steam clean the crankshaft surface immediately after
completing the test.
Note:
The ammonium cuprous chloride solution is highly
corrosive. Because of this, it is imperative that the
surfaces being tested be cleaned immediately after
completing the test.