Komatsu 4D98 Series Shop Manual page 125

9. Starting Motor
(d) Armature and commutator runout
-l
Use a dial gage and measure the arma-
ture core runout and commutator runout.
Correct or replace if the limit is exceeded.
(mm)
Commutator
Armature
Fig. 13
(e) Commutator surface inspection
If the commutator surface is roughened,
grind with #I500 to #600 emery cloth.
Fig. 14
(f) Commutator insulation depth
Measure the depth of the insulating mate-
rial between commutator segments, and
correct it if it is less than the limit.
(mm)
lnsulatina
materials
Chamfering
0..5-0.8mm
1
I
Abnormal
Normal
I
Fig. 15
9-9