Starter Armature: Testing and Inspection

Armature Shaft Bush
Inspect bush for wear or damage. Replace if necessary.

Armature




- Inspect commutator for dirt or burn. Correct with sandpaper or lathe, if necessary.
- Check commutator for uneven wear with armature (1) supported on V-blocks (2). If deflection of dial gauge pointer exceeds limit, repair or replace.






NOTE: Below specification presupposes that armature is free from bend. Bent armature must be replaced.

Commutator out of round
Standard: 0.05 mm (0.002 in.) or less
Limit: 0.4 mm (0.016 in.)




- Inspect commutator for wear. If diameter is below limit, replace armature.

Commutator outside diameter
Standard: 29.4 mm (1.16 in.)
Limit: 28.8 mm (1.13 in.)




- Inspect commutator for insulator depth. Correct or replace if below limit.

Commutator insulator depth "a"
Standard: 0.4 - 0.6 mm (0.016 - 0.024 in.)
Limit: 0.2 mm (0.008 in.)




Ground test
Check commutator and armature core. If there is continuity, armature is grounded and must be replaced.




Open circuit test
Check for continuity between segments. If there is no continuity at any test point, there is an open circuit and armature must be replaced.