CHARGING & STARTING SYSTEM
Page 2B-30 90-855347R1 JANUARY 1999
Starter Cleaning, Inspection and Testing
Cleaning and Inspection
1. Clean all starter motor parts.
2. Check pinion teeth for chips, cracks or excessive wear.
3. Replace the drive clutch spring and/or collar if tension is not adequate or if wear is
excessive.
4. Inspect brush holder for damage or for failure to hold brushes against commutator.
5. Replace brushes that are pitted or worn to less than 1/4 in. (6.4 mm) in length.
6. Inspect the armature conductor (commutator bar junction) for a tight connection. A
loose connection (excessive heat from prolonged cranking melts solder joints) results
in a burned commutator bar.
7. Resurface and undercut a rough commutator as follows:
CAUTION
Do not turn down the commutator excessively.
a. Resurface the commutator and undercut the insulation between the commutator
bars 1/32 in. (0.8mm) to the full width of the insulation and so that the undercut
is flat.
b. Clean the commutator slots after undercutting.
c. Sand the commutator lightly with No. 00 sandpaper to remove burrs, then clean
the commutator.
d. Recheck the armature on a growler for shorts as specified in the following proce-
dure (“Testing”).
8. Open-circuited armatures often can be repaired. The most likely place for an open cir-
cuit is at the commutator bars, as a result of long cranking periods. Long cranking peri-
ods overheat the starter motor so that solder in the connections melts and is thrown
out. The resulting poor connections then cause arcing and burning of the commutator
bars.
9. Repair bars, that are not excessively burned, by resoldering the leads in bars (using
rosin flux solder) and turning down the commutator in a lathe to remove burned mate-
rial, then undercut the mica.
10. Clean out the copper or brush dust from slots between the commutator bars.
11. Check the armature for ground. See the following procedure (“Testing”).
Testing
Armature Test for Shorts
Check armature for short circuits by placing on growler and holding hack saw blade over
armature core while armature is rotated. If saw blade vibrates, armature is shorted. Re-
check after cleaning between commutator bars. If saw blade still vibrates, replace arma-
ture.
11669
To Next Page
Loading...
Need help?
General
