Starter Armature: Testing and Inspection

Armature




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 supported on V-blocks. If deflection of dial gauge pointer exceeds limit, repair or replace.

Commutator out of round
Standard : 0.05 mm (0.002 in.) or less
Limit : 0.4 mm (0.015 in.)

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




- 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 (0.015 - 0.023 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.