Isuzu KB P190. Manual — part 256

ENGINE ELECTRICAL 6D – 23

DISASSEMBLY

RTW460LF000201

Disassembly Step

1. Lead wire

14.

Armature

2. Bolt

15.

Bolt

3. Magnetic switch assembly

16.

Bearing retainer

4. Torsion spring

17.

Pinion assembly

5. Plunger

18.

Pinion stopper clip

6. Dust cover

19.

Pinion stopper

7. Magnetic switch

20.

Return spring

8. Screw

21.

Pinion shaft

9. Through bolt

22.

Clutch

10. Rear cover

23.

Dust cover

11. Motor assembly

24.

Shift lever

12. Brush holder

25.

Gear case

13. Yoke

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.

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.

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.