Section 12 (Starting/Charging Systems (H4SO)): Starter: Inspection: Armature

WARNING: This page is about a different variant/trim than selected.

Check commutator for any sign of burns of rough surfaces or stepped wear. If wear is of a minor nature, correct it by using sand paper.
Run-out test
Check the commutator run-out and replace if it exceeds the limit.

Commutator run-out: Standard

0.02 mm (0.0008 in), or less Service limit

Less than 0.05 mm (0.0020 in)

Fig 1: Checking Commutator Run-Out
Courtesy of SUBARU OF AMERICA, INC.
Depth of segment mold
Check the depth of segment mold.

Depth of segment mold: 0.6 mm (0.024 in)

Limit

0.2 mm (0.008 in)

Fig 2: Identifying Depth Of Segment Mold
Courtesy of SUBARU OF AMERICA, INC.
Armature short-circuit test
Check armature for short-circuit by placing it on growler tester. Hold a iron sheet against armature core while slowly rotating armature. A short-circuited armature will cause the iron sheet to vibrate and to be attracted to core. If the iron sheet is attracted or vibrates, the armature, which is short-circuited, must be replaced or repaired.

Fig 3: Checking Armature Short-Circuit
Courtesy of SUBARU OF AMERICA, INC.
Armature ground test
Using circuit tester, touch one probe to the commutator segment and the other to shaft. If there is no continuity, it is normal. If there is a continuity armature is grounded. Replace armature if it is grounded.

Fig 4: Checking Armature Ground
Courtesy of SUBARU OF AMERICA, INC.