Isuzu A-4JB1 Repair Manual

ENGINE ASSEMBLY ( 2 )
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.
65
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.
The portion to be tested
shall be held horizontally
so as not to let the test
solution flow.
The sliding surface
of the pin
or journal.
Test liquid should
not be applied to
the area around the
oil port.
Approximately
10mm
Judgment
1. Wait for thirty to forty seconds.
If there is no discoloration after thirty or forty sec-
onds, 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.

Isuzu A-4JB1 Specifications

General

Brand	Isuzu
Model	A-4JB1
Category	Engine
Language	English