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


Pinion Clearance - Adjust

Usage:

769C 01X

37-MT Starting Motors (12 Volt Systems)




Illustration 1g00810014

Connections for pinion clearance check for 12 volt system

(1) Battery

(2) Starting motor

(3) Solenoid mounting bolt




Illustration 2g00810097

(4) Adjustment nut

(5) Pinion drive housing

(6) Pinion

(7) Retainer

(X) Pinion clearance

When the solenoid is installed, make an adjustment of the pinion clearance. The adjustment should be made with the starting motor removed.

  1. Disconnect the terminal connector for the starting motor "MTR" from the solenoid.

  1. Connect the battery to the solenoid per Illustration 1. The illustration shows a 12 volt system with a battery that is connected in series to a starting motor. Connect the negative side of the battery cable to the solenoid mounting bolt (3) of the starting motor (2).

  1. Temporarily, touch a wire from the solenoid mounting bolt terminal (3) to the "MTR" terminal. The pinion will shift to the crank position and the pinion will stay there until the battery is disconnected.

  1. Push the pinion toward the commutator in order to remove free movement.

  1. Measure the clearance (X) from the pinion (6) to the pinion drive housing (5). Pinion clearance (X) must be 1.0 ± 0.8 mm (0.04 ± 0.03 inch).

  1. If the clearance is not correct, remove the plug on the shift lever housing (5). Turn the adjustment nut (4) until the clearance is correct. Turning the nut clockwise will decrease the clearance (X) .

    Note: The plunger may turn when the adjustment nut (4) is being turned. If the plunger turns, disconnect the battery from the solenoid. Remove the solenoid from the starting motor. Hold the plunger from turning and adjust the nut (4). This procedure may need to be performed several times until the correct clearance is obtained.

  1. Disconnect the batteries and install the plug into the shift lever housing (5) .

37-MT Starting Motors (24 Volt Systems)




Illustration 3g00810110

Connections for pinion clearance check for 24 volt system

(1) Battery




Illustration 4g00810097

(4) Adjustment nut

(5) Pinion drive housing

(6) Pinion

(7) Retainer

(X) Pinion clearance

When the solenoid is installed, make an adjustment of the pinion clearance. The adjustment should be made with the starting motor removed.

  1. Disconnect the terminal connector of the starting motor "MTR" from the solenoid.

  1. Connect the battery to the solenoid per Illustration 3. The Illustration shows a 24 volt system with two 12 volt batteries that are connected in series to a starting motor. Connect the positive side of the battery cable to the "S" terminal. Connect the negative side of the battery cable to the "G" terminal of the starting motor.

  1. Temporarily, touch a wire from the "G" terminal to the "MTR" terminal. The pinion (6) will shift to the crank position and the pinion will stay there until the battery is disconnected.

  1. Push the pinion toward the commutator in order to remove free movement.

  1. Measure the clearance (X) from the pinion (6) to the pinion drive housing (5). Pinion clearance (X) must be 1.0 ± 0.8 mm (0.04 ± 0.03 inch).

  1. If the clearance is not correct, remove the plug on the shift lever housing (5). Turn the adjustment nut (4) until the clearance is correct. Turning the nut clockwise will decrease the clearance (X) .

    Note: The plunger may turn when the adjustment nut (4) is being turned. If the plunger turns, disconnect the battery from the solenoid. Remove the solenoid from the starting motor. Hold the plunger from turning and adjust the nut (4). This procedure may need to be performed several times until the correct clearance is obtained.

  1. Disconnect the batteries (1) and install the plug into the shift lever housing (5) .

41-MT Starting Motors (12 Volt Systems)




Illustration 5g00810014

Connections for pinion clearance check for 12 volt system

(1) Battery

(2) Starting motor

(3) Solenoid mounting bolt




Illustration 6g00810097

(4) Adjustment nut

(5) Pinion drive housing

(6) Pinion

(7) Retainer

(X) Pinion clearance

When the solenoid is installed, make an adjustment of the pinion clearance. The adjustment should be made with the starting motor removed.

  1. Disconnect the terminal connector for the starting motor (MTR) from the solenoid.

  1. Connect the battery to the solenoid per Illustration 5. The Illustration shows a 12 volt system with a battery that is connected in series to a starting motor. Connect the negative side of the battery cable to the solenoid mounting bolt (3) of the starting motor.

  1. Temporarily, touch a wire from the solenoid mounting bolt terminal (3) to the "MTR" terminal. The pinion will shift to the crank position and the pinion will stay there until the battery is disconnected.

  1. Push the pinion (6) toward the commutator in order to remove free movement.

  1. Measure the clearance (X) from the pinion (6) to the pinion drive housing (5). Pinion clearance (X) must be 4.57 ± 0.76 mm (0.18 ± 0.03 inch).

  1. If the clearance is not correct, remove the plug on the shift lever housing (5). Turn the adjustment nut (4) until the clearance is correct. Turning the nut clockwise will decrease the clearance (X) .

    Note: The plunger may turn when the adjustment nut (4) is being turned. If the plunger turns, disconnect the battery from the solenoid. Remove the solenoid from the starting motor. Hold the plunger from turning and adjust the nut (4). This procedure may need to be performed several times until the correct clearance is obtained.

  1. Disconnect the batteries (1) and install the plug into the shift lever housing (5) .

41-MT Starting Motors (24 Volt Systems)




Illustration 7g00810101



Illustration 8g00716455

Pinion clearance check

(1) Adjustment nut

(2) Pinion drive housing

(3) Pinion

(X) Pinion clearance

When the solenoid is installed, make an adjustment of the pinion clearance. The adjustment should be made with the starting motor removed.

  1. Disconnect the starting motor negative wire from the "G" ground terminal of the solenoid.

  1. Connect the batteries to the solenoid per Illustration 7. The Illustration shows a 24 volt system with two 12 volt batteries that are connected in series to a starting motor. Connect four 8 volt batteries in series for a 32 volt system. Connect eight 8 volt batteries in series for a 64 volt system. Connect the positive side of the battery cable to the "S" terminal of the starting motor solenoid. Connect the negative side of the battery cable to the "G" terminal of the starting motor.

  1. Temporarily, touch a wire from the "G" terminal to the "MTR" terminal. The pinion will shift to the crank position and the pinion will stay there until the battery is disconnected.

  1. Push the pinion toward the commutator in order to remove free movement.

  1. Measure the clearance (X) from the pinion (3) to the pinion drive housing (2). Pinion clearance (X) must be 9.10 ± 0.8 mm (0.36 ± 0.03 inch).

  1. If the clearance is not correct, remove the plug on the shift lever housing (2). Turn the adjustment nut (1) until the clearance is correct. Turning the nut clockwise will decrease the clearance (X) .

    Note: The plunger may turn when the adjustment nut (1) is being turned. If the plunger turns, disconnect the battery from the solenoid. Remove the solenoid from the starting motor. Hold the plunger from turning and adjust the nut (1). This procedure may need to be performed several times until the correct clearance is obtained.

  1. Disconnect the batteries and install the plug into the shift lever housing (2) .

42-MT Starting Motors (12 Volt Systems)




Illustration 9g00810014

Connections for pinion clearance check for 12 volt system

(1) Battery

(2) Starting motor

(3) Solenoid mounting bolt




Illustration 10g00810097

(4) Adjustment nut

(5) Pinion drive housing

(6) Pinion

(7) Retainer

(X) Pinion clearance

When the solenoid is installed, make an adjustment of the pinion clearance. The adjustment should be made with the starting motor removed.

  1. Disconnect the terminal connector of the starting motor (MTR) from the solenoid.

  1. Connect the battery to the solenoid per Illustration 9. The Illustration shows a 12 volt system with a battery that is connected in series to a starting motor. Connect the negative side of the battery cable to the solenoid mounting bolt (3) of the starting motor.

  1. Temporarily, touch a wire from the solenoid mounting bolt terminal (3) to the "MTR" terminal. The pinion (6) will shift to the crank position and the pinion will stay there until the battery is disconnected.

  1. Push the pinion toward the commutator in order to remove free movement.

  1. Measure the clearance (X) from the pinion (6) to the pinion drive housing (5). Pinion clearance (X) must be 9.10 ± 0.8 mm (0.36 ± 0.03 inch).

  1. If the clearance is not correct, remove the plug on the shift lever housing (5). Turn the adjustment nut (4) until the clearance is correct. Turning the nut clockwise will decrease the clearance (X) .

    Note: The plunger may turn when the adjustment nut (4) is being turned. If the plunger turns, disconnect the battery from the solenoid. Remove the solenoid from the starting motor. Hold the plunger from turning and adjust the nut (4). This procedure may need to be performed several times until the correct clearance is obtained.

  1. Disconnect the batteries and install the plug into the shift lever housing.

42-MT Starting Motors (24 Volt Systems)




Illustration 11g00810101

Connections for pinion clearance check for 24 volt system




Illustration 12g00716455

Pinion clearance check

(1) Adjustment nut

(2) Pinion drive housing

(3) Pinion

(X) Pinion clearance

When the solenoid is installed, make an adjustment of the pinion clearance. The adjustment should be made with the starting motor removed.

  1. Disconnect the starting motor negative wire from the "G" ground terminal of the solenoid.

  1. Connect the batteries to the solenoid per Illustration 11. The Illustration shows a 24 volt system with two 12 volt batteries that are connected in series to a starting motor. Connect four 8 volt batteries in series for a 32 volt system. Connect eight 8 volt batteries in series for a 64 volt system. Connect the positive side of the battery cable to the "S" terminal of the starting motor solenoid. Connect the negative side of the battery cable to the "G" terminal of the starting motor.

  1. Temporarily, touch a wire from the "G" terminal to the "MTR" terminal. The pinion will shift to the crank position and the pinion will stay there until the battery is disconnected.

  1. Push the pinion toward the commutator in order to remove free movement.

  1. Measure the clearance (X) from the pinion to the pinion drive housing. Pinion clearance (X) must be 9.10 ± 0.8 mm (0.36 ± 0.03 inch).

  1. If the clearance is not correct, remove the plug on the shift lever housing (2). Turn the adjustment nut (1) until the clearance is correct. Turning the nut clockwise will decrease the clearance (X) .

    Note: The plunger may turn when the adjustment nut (1) is being turned. If the plunger turns, disconnect the battery from the solenoid. Remove the solenoid from the starting motor. Hold the plunger from turning and adjust the nut (1). This procedure may need to be performed several times until the correct clearance is obtained.

  1. Disconnect the batteries and install the plug into the shift lever housing.
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