37-MT, 41-MT, and 42-MT Series Starting Motors Caterpillar

Disassemble the Starting Motor

Start By:

1. Remove the starting motor from the machine.

Note: The disassembly of the 12 volt starting motor is similar to the disassembly of the 24 volt starting motor.

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Illustration 1	g00810179

1. Disconnect and remove shunt wire assembly (4) and motor terminal connector "MTR" (3) from the solenoid (1) and starting motor.

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Illustration 2	g00820183

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Illustration 3	g00810580

2. Remove the plug (5) and seal from the shift lever housing. Remove the nut (6) that is inside the shift lever housing. The nut holds the plunger to the shift lever.

3. Remove bolts (2) and solenoid (1) from the shift lever housing. Do not disassemble the solenoid. The parts inside the solenoid are not serviceable.

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Illustration 4	g00810222

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Illustration 5	g00810478

4. Mark the following components for correct assembly: rear housing (8), pinion drive, shift lever housing and starting motor housing. Remove four bolts (7) and rear housing (8). Remove washer (9) from the armature. Remove the O-ring seal from the starting motor housing, if necessary.

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Illustration 6	g00810242

5. Remove bushing (10) from the rear housing, if necessary.

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Illustration 7	g00810245

6. Lift each brush spring (12) and put the spring on the left side of the brush (14). Disconnect three leads (11) and remove brush holder (13) .

7. Remove brushes (14) from the brush holder.

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Illustration 8	g00810249

8. Remove six bolts (16) and pinion drive housing (15) .

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Illustration 9	g00810257

9. Remove bushing (17) from the pinion drive housing, if necessary.

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Illustration 10	g00810266

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Illustration 11	g00810429

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Illustration 12	g00810272

10. Drive retainer (18) backward away from ring (20) that is below the retainer. Remove the ring and the retainer. Remove armature (19) from pinion drive (21) and the starting motor and the shift lever housing (23). Remove the washer (22) from the armature (19) .

    Note: The pinion drive that is on the 41-MT starting motor is not the same pinion drive that is shown. The pinion drive is similar to a 42-MT starting motor. Refer to Disassembly and Assembly, "Starting Motor - Disassemble".

11. Remove pinion drive (21) from the shift lever forks (25) .

12. Remove five bolts (26) and shift lever housing (23). Remove ring (24) with tool (A), pin (27) and shift lever (25). Remove the seals from the pin, if necessary.

13. Remove the O-ring seal from the shift lever housing, if necessary.

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Illustration 13	g00810276

14. Remove seal (28) and bushing (29) from the shift lever housing, if necessary.

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Illustration 14	g00810281

15. Remove eight screws (32), field winding coil (30), and pole shoes (31) from the starting motor housing. It may be necessary to use an impact driver to remove screws (32). One of the screws is the negative terminal.

16. Clean the armature, field winding coil, and pinion drive with mineral spirits and a brush.

    Note: If the commutator is dirty, the commutator may be cleaned with Number 00 sandpaper. Do not use emery cloth.

17. Inspect all parts for wear and damage.