1) Checking positive diode
Check for continuity between the diode lead and
the positive side heat sink. The positive diode is in
good condition if continuity exists only in the direc-
tion from the diode lead to the heat sink.
S6M0406A
(A) Diode lead
(B) Heat sink (Positive side)
2) Checking negative diode
Check for continuity between the negative side
heat sink and diode lead. The negative diode is in
good condition if continuity exists only in the direc-
tion from the heat sink to the diode lead.
S6M0407A
(A) Diode lead
(B) Heat sink (Negative side)
2. ROTOR
1) Slip ring surface
Inspect slip rings for contamination or any rough-
ness of the sliding surface. Repair slip ring surface
using a lathe or sand paper.
2) Slip ring outer diameter
Measure slip ring outer diameter. If slip ring is worn
replace rotor assembly.
Slip ring outer diameter:
Standard
22.7 mm (0.894 in)
Limit
22.1 mm (0.870 in)
3) Continuity test
Check resistance between slip rings using circuit
tester.
If the resistance is not within specification, replace
rotor assembly.
Specified resistance:
Approx. 2.7 Ð 3.2
W
G6M0075
4) Insulation test
Check continuity between slip ring and rotor core
or shaft. If continuity exists, the rotor coil is
grounded, and so replace rotor assembly.
G6M0076
5) Ball bearing (rear side)
(1) Check rear ball bearing. Replace if it is
noisy or if rotor does not turn smoothly.
(2) The rear bearing can be removed by using
common bearing puller.
G6M0077
14
6-1[W2C2]SERVICE PROCEDURE
2. Generator
3. STATOR
1) Continuity test
Inspect stator coil for continuity between each end
of the lead wires. If there is no continuity between
individual lead wires, the lead wire is broken, and
so replace stator assembly.
S6M0408
2) Insulation test
Inspect stator coil for continuity between stator
core and each end of the lead wire. If there is
continuity, the stator coil is grounded, and so
replace stator assembly.
G6M0079
4. BRUSH
1) Measure the length of each brush. If wear
exceeds the service limit, replace the brush. Each
brush has the service limit mark (A) on it.
Brush length:
Standard
18.5 mm (0.728 in)
Service limit
5.0 mm (0.197 in)
H6M0499C
2) Checking brush spring for proper pressure
Using a spring pressure indicator, push the brush
into the brush holder until its tip protrudes 2 mm
(0.08 in). Then measure the pressure of the brush
spring. If the pressure is less than 2.648 N (270 g,
9.52 oz), replace the brush spring with a new one.
The new spring must have a pressure of 4.609 to
5.786 N (470 to 590 g, 16.58 to 20.81 oz).
G6M0143
5. BEARING (FRONT SIDE)
1) Check front ball bearing. If resistance is felt
while rotating, or if abnormal noise is heard,
replace the ball bearing.
2) Replacing front bearing
(1) Remove front bearing retainer.
(2) Closely install a fit tool on the bearing inner
race. Press the bearing down out of front
bracket with a hand press or vise. A socket
wrench can serve as the tool.
S6M0409A
(A) Front bracket
(B) Socket wrench
15
[W2C5]6-1SERVICE PROCEDURE
2. Generator
