Isuzu A-4JA1 User Manual

Rocker Arm Shaft Outside Diameter
Use a micrometer to measure the rocker arm fitting
portion outside diameter.
If the measured value is less than the specified limit, the
rocker arm shaft must be replaced.
Rocker Arm Shaft Outside Diameter mm(in)
Standard Limit
18.98 – 19.00 (0.747 – 0.748) 18.85 (0.742)
ENGINE ASSEMBLY ( 2 )
ROCKER ARM SHAFT AND ROCKER ARM
Rocker Arm Shaft Run-Out
1. Place the rocker arm shaft on a V-block.
2. Use a dial indicator to measure the rocker arm shaft
central portion run-out.
If the run-out is very slight, correct the rocker arm
shaft run-out with a bench press. The rocker arm
must be at cold condition.
If the measured rocker arm shaft run-out exceeds
the specified limit, the rocker arm shaft must be
replaced.
Rocker Arm Shaft Run-Out mm(in)
Standard Limit
0.2 (0.008) 0.6 (0.024)
54
Rocker Arm Shaft and Rocker Arm Clearance
1. Use either a vernier caliper or a dial indicator to
measure the rocker arm bushing inside diameter.
Rocker Arm Bushing Inside Diameter mm(in)
Standard Limit
19.01 – 19.03 (0.748 – 0.749) 19.05 (0.750)
2. Measure the rocker arm shaft outside diameter.
If the measured value exceeds the specified limit,
replace either the rocker arm or the rocker arm shaft.
Rocker Arm and Rocker Arm Shaft Clearance mm(in)
Standard Limit
0.01 – 0.05 (0.0004 – 0.002) 0.2 (0.008)

Isuzu A-4JA1 Specifications

General

Brand	Isuzu
Model	A-4JA1
Category	Engine
Language	English