Isuzu NHR 4J Series, Workshop Manual

Page: 101 / 406

6A – 34 GENERAL ENGINE MECHANICAL
3. Run-out
1) Carefully set the crankshaft on the V-blocks.
Slowly rotate the crankshaft and measure the runout.
If the crankshaft runout exceeds the specified limit, the
crankshaft must be replaced.
Run-Out mm (in)
Standard Limit
0.05 (0.0020)
or less
0.08 (0.0031)
Measure the diameter and the uneven wear of main
journal and crank pin.
If the crankshaft wear exceeds the specified limit,
crankshaft must be replaced.
mm (in)
Standard Limit
Main journal
diameter 69.917-69.932
(2.7526 - 2.7532)
69.91 (2.7524)
Crank pin
diameter 52.915 - 52.930
(2.0833)
52.90 (2.0843)
Uneven wear
limit 0.05 (0.0020)
or less
0.08 (0.0031)
Crankshaft inspection
Inspect the surface of the crankshaft journals and crank
pins for excessive wear and damage.
Inspect the oil seal fitting surfaces for excessive wear and
damage.
Inspect the oil ports for obstructions.
Crankshaft tufftriding inspection
The portion to be tested must be held horizontally so as
not let the test solution flow.
Test liquid should not be applied to the area around the oil
port.
The sliding surface of the pin or journal.
Approximately 10mm
NOTE:
To increase crankshaft strength, Tufftride Method
(Soft nitriding) has been applied. Because of this, it is
not possible to regrind the crankshaft surfaces.
1. Use an organic cleaner to thoroughly clean the
crankshaft. There must be no traces of oil the surfaces
to be inspected.
2. Prepare a 5-10% solution of ammonium cupric
chloride (dissolved in distilled water).
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