Isuzu NKR 4J Series - Camshaft, Tappet Inspection and Repair

6A – 18 GENERAL ENGINE MECHANICAL
6a. Camshaft Timing Pulley (Belt Drive Model)
• Use the timing pulley puller
"
to remove the pulley.
Timing Pulley Puller: 5-8840-0086-0
• Remove the stopper bolt.
7. Camshaft Thrust Plate (Gear Drive Model)
7a. Camshaft Pulley Center (Belt Drive Model)
8. Camshaft
9. Tappet
INSPECTION AND REPAIR
Make the necessary adjustment, repairs, and part
replacements if excessive wear or damage is discovered
during inspection.
1. Measure the Camshaft Thrust Clearance
• Use a dial indicator to measure the camshaft end play.
This must be done before removing the camshaft
gear.
If the camshaft end play exceeds the specified limit,
the thrust plate must be replaced.
Camshaft End Play mm (in)
Standard Limit
0.08 (0.0031) 0.2 (0.0079)
2. Camshaft Journal Diameter
• Use a micrometer to measure each camshaft journal
diameter in two directions
!
and
"
. If the measured
value is less than the specified limit, the camshaft
must be replaced.
Journal Diameter mm (in)
Standard Limit
49.945 - 49.975 (1.9663 - 1.9675) 49.60 (1.9528)
3. Cam Height
• Measure the cam height
H
with a micrometer. If the
measured value is less than the specified limit, the
camshaft must be replaced.
Cam Height mm (in)
Standard Limit
42.02 (1.6543) 41.65 (1.6398)
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