Inspection And Repair - Isuzu 4JA1 Workshop Manual

6D – 26 ENGINE ELECTRICAL
Make the necessary adjustments, repairs, and part replacement if excessive wear or damage is discovered during
inspection.

INSPECTION AND REPAIR

ARMATURE
1. Measure the commutator run-out.
Commutator Run-Out
RTW46DSH003501
2. Check the commutator mica segments for excessive
3.
Mica Segment Depth
If the mica segment depth is less than the standard but
more than the limit, the commutator may be reground.
If the mica segment depth is less than the limit, the
065RY00025
commutator must be replaced.
4. Measure the commutator outside diameter.
Commutator Outside Diameter
If the measured outside diameter is less than the specified
limit, the commutator must be replaced.
065RY00026
5. Use a circuit tester to check the armature for
RTW46DSH003601
Replace the commutator if the measured run-out
exceeds the specified limit.
Standard
0.05 (0.002)
wear.
Measure the mica segment depth.
Standard
0.5 ∼ 0.8 (0.020 ∼ 0.030)
Standard
36.5 (1.44)
grounding.
1 Hold one probe of the circuit tester against the
commutator segment.
2 Hold the other circuit tester probe against the
armature core.
If the circuit tester indicates continuity, the armature is
grounded.
The armature must be replaced.
mm (in)
Limit
0.2 (0.008)
mm (in)
Limit
0.2 (0.008)
mm (in)
Limit
35.5 (1.40)