Service Manual

ELECTRICAL SYSTEM 8-19
Starter System
Armature Inspection
•
Inspect the surface of the commutator [A].
If it is scratched or dirty, polish it with a piece of very fine emery cloth
[B], and clean out the grooves.
•
Measure the depth of the grooves between the commutator segments.
If the grooves are shallower than the specified limit, replace the
armature with a new one.
If the grooves are only dirty, clean them carefully.
Commutator Groove Depth Limit
Less than 1.0 mm (0.039 in.)
[A] Bad
[B] Segment
[C] Good
[D] 1.0 mm (0.039 in.) limit
[E] Mica
•
Measure the commutator outside diameter [A] at several points.
If the diameter is less than the service limit, replace the armature with
a new one.
Commutator Outside Diameter
Service Limit: 29.5 mm (1.161 in.)
•
Support the armature in an alignment jig at each end of the shaft as
shown. Position a dial indicator perpendicular to the commutator.
•
Rotate the armature slowly and read the commutator runout.
If runout is more than the service limit, turn down the commutator or
replace the armature with a new one.
Commutator Runout
Service Limit: 0.0178 mm (0.0007 in.)
•
Test the armature winding for shorts.

Place the armature on a growler [A].

Hold a thin metal strip (e.g., hack saw blade) on top of the armature.

Turn on the growler and rotate the armature one complete turn.
If the metal strip vibrates, the windings are internally shorted to each
other and the starter motor must be replaced.