Page 1025 of 6020
6D – 24 ENGINE ELECTRICAL
RTW46DSH002601
Important Operations
1. Lead Wire
Disconnect the lead wire at the magnetic switch.
RTW46DSH002701
3. Magnetic Switch Assembly
Remove the magnetic switch bolts, then remove the
switch from the shift lever.
RTW46DSH002801
Remove the torsion spring from the magnetic switch.
RTW46DSH002901
8. Through Bolt
9. Screw
10. Rear Cover Remove the through bolts, then remove the rear cover.
RTW46DSH003001
11. Motor Assembly
Remove the four brushes from the brush holders.
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ISUZU KB P190 2007
Page 1026 of 6020
ENGINE ELECTRICAL 6D – 25
RTW46DSH003101
Remove the yoke along with the armature and the brush
holder from the gear case.
Remove the brushes and commutator carefully so as not
to allow them in contact with the adjacent parts.
RTW46DSH003201
12. Brush Holder
13. Yoke
14. Armature Remove the brush holder and pull out the armature
assembly free from the yoke.
RTW46DSH003301
16. Bearing Retainer
17. Pinion Assembly
23. Dust Cover
24. Shift Lever
25. Gear Case 1. Remove the bearing retainer.
2. Remove the pinion from the gear case.
RTW46DSH003401
3. Use a screwdriver to remove the stopper clip. Then
disassemble the pinion assembly.
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ISUZU KB P190 2007
Page 1027 of 6020

6D – 26 ENGINE ELECTRICAL
INSPECTION AND REPAIR
Make the necessary adjustments, repairs, and part replacement if excessive wear or damage is discovered during
inspection.
ARMATURE
1. Measure the commutator run-out. Replace the commutator if the measured run-out
exceeds the specified limit.
Commutator Run-Out mm (in)
Standard Limit
0.05 (0.002) 0.2 (0.008)
RTW46DSH003501
2. Check the commutator mica segments for excessive
wear.
3. Measure the mica segment depth.
Mica Segment Depth mm (in)
Standard Limit
0.5 ∼ 0.8 (0.020 ∼ 0.030) 0.2 (0.008)
065RY00025
If the mica segment depth is less than the standard but
more than the limit, the commutator may be reground.
If the mica segment depth is less than the limit, the
commutator must be replaced.
4. Measure the commutator outside diameter.
Commutator Outside Diameter mm (in)
Standard Limit
36.5 (1.44) 35.5 (1.40)
If the measured outside diameter is less than the specified
limit, the commutator must be replaced.
065RY00026
RTW46DSH003601
5. Use a circuit tester to check the armature for
grounding.
1 Hold one probe of the circuit tester against the commutator segment.
2 Hold the other circuit tester probe against the armature core.
If the circuit tester indicates continuity, the armature is grounded.
The armature must be replaced.
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ISUZU KB P190 2007
Page 1028 of 6020

ENGINE ELECTRICAL 6D – 27
RTW46DSH003701
6. Use the circuit tester to check the armature for
continuity.
1 Hold the circuit tester probes against two commutator segments.
2 Repear Step 1 at different segments of the armature core.
There should be continuity between all segments of the commutator.
If there is not, the armature must be replaced.
RTW46DSH003801
YOKE
1. Use a circuit tester to check the field winding ground.
1 Hold one circuit tester probe against the field winding end or brush.
2 Hold the other circuit tester probe against the bare surface of the yoke body.
There should be no continuity. If there is continuity, the field coil is grounded.
The yoke must be replaced.
RTW46DSH003901
2. Use the circuit tester to check the field winding
continuity.
1 Hold one circuit tester probe against the “M ”
terminal lead wire.
2 Hold the other circuit tester probe against the field winding brush.
There should be continuity. If there is no continuity, the yoke must be replaced.
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ISUZU KB P190 2007
Page 1029 of 6020

6D – 28 ENGINE ELECTRICAL
BRUSH AND BRUSH HOLDER
1. Use a vernier caliper to measure the brush length (four
brushes).
Replace the brushes as a set if one or more of the
brush lengths is less than the specified limit.
Brush Length mm (in)
Standard Limit
15 (0.59) 12 (0.47)
RTW46DSH004001
RTW46DSH004101
2. Use a circuit tester to check the brush holder
insulation.
Touch one probe to the holder plate and the other
probe to the positive brush holder.
There should be no continuity.
3. Inspect the brushes for excessive wear. If the negative brushes have excessive wear, the
entire brush holder assembly must be replaced.
If the positive brushes have excessive wear, the entire
yoke must be replaced.
OVERRUNNING CLUTCH
1. Inspect the overrunning clutch gear teeth for excessive wear and damage.
Replace the overrunning clutch if necessary.
2. Rotate the pinion clockwise. It should turn smoothly.
3. Try to rotate the pinion in the opposite direction. The pinion should lock.
065RY00035
RTW46DSH004401
BEARING
Inspect the bearings for excessive wear and damage.
Replace the bearings if necessary.
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ISUZU KB P190 2007
Page 1030 of 6020
ENGINE ELECTRICAL 6D – 29
REASSEMBLY
RTW46DLF000601
Reassembly Steps
1.
Magnetic switch assembly
14. Pinion stopper
2.
Magnetic switch 15. Pinion stopper clip
3.
Dust cover 16. Bearing retainer
4.
Plunger 17. Bolt
5.
Torsion spring 18. Motor assembly
6.
Shift lever
19. Armature
7.
Gear case 20. Yoke
8.
Dust cover 21. Brush holder
9.
Bolt 22. Rear cover
10.
Pinion assembly 23. Screw
11.
Clutch 24. Through bolt
12.
Pinion shaft 25. Lead wire
13.
Rerurn spring
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ISUZU KB P190 2007
Page 1031 of 6020
6D – 30 ENGINE ELECTRICAL
RTW46DSH005601
Important Operations
1. Magnetic Switch Assembly
1. Attach the torsion spring to the hole in the magnetic switch as illustrated.
2. Insert the shift lever into the plunger hole of the magnetic switch.
RTW46DSH005701
7. Gear Case
3,8. Dust Cover 1. Install the magnetic switch assembly in the gear case.
2. Install the dust cover.
Dust Cover Bolt Torque N⋅m (kg ⋅m/lb ⋅ft)
8 (0.8/5.4)
10. Pinion Assembly
Apply a coat of grease to the reduction gear and install the
pinion assembly to the armature shaft.
065RY00041
RTW46DSH004501
21. Brush Holders
1. Install the brushes into the brush holder with raising the spring end of the brush spring.
Take care not to damage the commutator face.
2. Install the brush holder with aligning the peripheries of the yoke and the brush holder.
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ISUZU KB P190 2007
Page 1032 of 6020
ENGINE ELECTRICAL 6D – 31
24. Through Bolt
Install the through bolts in the rear cover and tighten them
to the specified torque.
Through Bolt Torque N⋅m (kg ⋅m/lb ⋅ft)
8.1 (0.83/6.00)
065RY00044
RTW46DSH002601
25. Lead Wire
Connect the lead wire in the magnetic switch and tighten
the terminal nut to the specified torque.
Lead Wire Terminal Nut Torque N ⋅m (kg ⋅m/lb ⋅ft)
8.6 (0.88/6.40)
RTW46DSH005801
Inspection After Assembly
Use a vernier caliper to measure the pinion shaft thrust
play.
The pinion shaft thrust play is equal to the pinion shaft end
and pinion stopper clearance.
Pinion Shaft Thrust Play mm (in)
0.1 – 2.0 (0.004 – 0.078)
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ISUZU KB P190 2007