Komatsu 4D98 Series Shop Manual page 164

10. Alternator
10.2.5 Inspection and Maintenance
(1) Rotor
a) Slip ring wear limit
Measure the outside diameter of the slip
ring. If it is worn by 1 mm or more from the
standard dimension, replace the slip ring.
b) Slip ring surface inspection
Outside diameter (mm)
jx$zj-Gq
Check the slip ring surface
ness and no oil adhesion.
for smooth-
If roughened, correct with a sandpaper,
and wipe with cloth wetted with alcohol if
stained.
c) Rotor coil continuity check
Use a circuit tester and check continuity
between slip rings.
[ D$ccretonJ Replace the rotor.
d) Rotor coil insulation test
Use a circuit tester and check continuity
between the slip ring and rotor core or
shaft.
Replace the rotor.
er
Fig. 23
Tester
\ Slip ring
Fig. 24
\ Slip ring
Fig. 25
lo-18