Service Manual

S-73
SM-E2B SERIES, WSM
DIESEL ENGINE
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.
Electromagnetic
drive type
28.0 mm
1.102 in.
Planetary gear
reduction type
30.0 mm
1.181 in.
Allowable
limit
Electromagnetic
drive type
27.0 mm
1.063 in.
Planetary gear
reduction type
29.0 mm
1.142 in.
Difference of
O.D.’s
Factory
spec.
Electromagnetic
drive type
Less than 0.05 mm
0.002 in.
Planetary gear
reduction type
Less than 0.02 mm
0.0008 in.
Allowable
limit
Electromagnetic
drive type
0.4 mm
0.016 in.
Planetary gear
reduction type
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 06, 2006 A