Komatsu 4D98 Series Shop Manual page 165

10. Alternator
e) Ball bearing inspection
Inspect the rear side ball bearing. If the
rotation is heavy or any abnormal sound is
heard, replace the ball bearing.
Fig. 26
10.2.6 Reassembly Procedure
Reverse the disassembly procedure with attention paid to the following points:
(1) See section 10.2.2 for the tightening torque of each part.
1) Reassembly on front and rear sides
a)
Always replace the ball bearing on the rear side after disassembling the alternator.
b)
Two nylon bands are embedded in the outer race of the ball bearing on the rear side
with slight protrusion from the outer surface of the bearing. The nylon bands, there-
fore, will be cut unless the rear bracket is heated as in the case of disassembly.
c) Insert a pin from the outside of the bracket
and push the brush into the brush holder.
d) Before reassembly, raise the temperature at
the center of the rear bracket by approx.
50°C (to 70°C or more when the room tem-
perature is 20°C) by blowing with a dryer
as in the case of the rear bracket disas-
sembly.
Dryer conditions
Dryer :1 to1.5kW
Time : 1 minute
Distance : From the upper side
Fig. 27
L
Fig. 26