S-105
03-M Series, WSM
DIESEL ENGINE
Armature Coil
1. Check the continuity across the commutator and armature coil
core with resistance range of circuit tester.
2. If it conducts, replace the armature.
3. Check the continuity across the segments of the commutator with
resistance range of circuit tester.
4. If it dose not conduct, replace the armature.
W1156507
Commutator and Mica
1. Check the contact of the commutator for wear, and grind the
commutator with emery paper if it is slightly worn.
2. Measure the commutator O.D. with an outside micrometer at
several points.
3. If the minimum O.D. is less than the allowable limit, replace the
armature.
4. If the difference of the O.D.'s exceeds the allowable limit, correct
the commutator on a lathe to the factory specification.
5. Measure the mica undercut.
6. If the undercut is less than the allowable limit, correct it with a saw
blade and chamfer the segment edges.
W1155802
Commutator O.D.
Factory spec.
30.0 mm
1.181 in.
Allowable limit
29.0 mm
1.142 in.
Difference of O.D.’s
Factory spec.
Less than 0.02 mm
0.0008 in.
Allowable limit
0.05 mm
0.0020 in.
Mica under cut
Factory spec.
0.50 to 0.80 mm
0.0197 to 0.0315 in.
Allowable limit
0.20 mm
0.0079 in.
(1) Segment
(2) Depth of Mica
(3) Mica
(a) Correct
(b) Incorrect
KiSC issued 08, 2012 A
