Starting Motor Solenoid - Replace {1467} Caterpillar

Caterpillar Products

All Machines

Introduction

This instruction describes the removal process and the installation process for the following semi-solid link solenoids: 37MT, 41MT, 42MT, 50MT

Before you begin the following procedures, determine the series of the starting motor that is to be replaced. The series number is stamped in the Series Block which is on the starting motors part number tag.

Note: Before replacing the solenoid, remove the starting motor. Ensure that the starting motor is disconnected from the vehicle.

Solenoid Removal Instructions

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Illustration 1	g03105237
1/2 inch Solenoid motor terminal nut (42MT models)

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Illustration 2	g03105279
1/4 inch Solenoid motor terminal screw (37MT and 41MT models)

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Illustration 3	g03106036
1/2 inch Solenoid motor terminal screw (50MT models)

1. For 42MT and 50MT models, loosen the 1/2 inch nut on the solenoid motor terminal. For 37MT models and 41MT models, loosen the 1/4 inch screw (2) on the solenoid motor terminal.
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   Illustration 4	g03105317
   Starting motor (1) Solenoid motor terminal nut (3) Gasket (4) Lever housing register (5) Mounting screws (6) Solenoid (7) Solenoid ground terminal (8) Solenoid switch terminal (9) Screw (10) Motor field connector strap

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   Illustration 5	g03105364
   Starting motor (11) Access plug (12) Plunger nut - 1/2 inch (13) Shift lever housing (14) Plunger rod (15) Plunger assembly (16) Pinion

2. Remove the 1/4 inch screw (9) at the motor field terminal.

3. For 42MT and 50MT models, remove 1/2 inch nut (1) from the solenoid motor terminal. For 37MT models and 41MT models, remove 1/4 inch screw (2) from the solenoid motor terminal.

4. Remove motor field connector strap (10).

5. For insulated models, perform Steps 5.a through 5.c.

   1. Remove the top nut and washer assembly from the solenoids ground terminal (7).

   2. Dispose of the top nut and washer assembly.

   3. Remove the ground lead from the solenoids ground terminal.

6. Remove three solenoid mounting screws (5).

   Note: Some solenoids will have four mounting screws on the base of the solenoid.

7. Remove access plug (11) and gasket (3) from shift lever housing (13).

8. Remove 1/2 inch plunger nut (12) carefully by following Steps 8.a through 8.d.

   Note: Proper care must be exercised when completing these steps to avoid personal injury and damage to the solenoid rubber boot. To avoid overheating the solenoid coils, power should not be applied more than 1 minute.

   1. Check required voltage (12V or 24V) stamped on solenoid bracket to energize solenoid.

   2. Apply appropriate power (12V or 24V) to solenoid between the "S" terminal (8) and solenoid ground terminal (7).

   3. Remove the 1/2" plunger nut (12). Dispose of the plunger nut.

   4. Remove power immediately after nut is removed.

9. Remove complete solenoid (6) and plunger assembly (15).

Illustration 6	g00811560
Measure the pinion clearance between the gear end of the pinion and theinside thenose housing bushing.

Solenoid Replacement Instructions for Semi-Solid Link Solenoid

Use the replacement semi-solid link solenoid to perform the following steps.

1. Slide the solenoid over lever housing register (4).

   1. Ensure that the flat flange of the solenoid body aligns with the flat flange of the housing.

   2. Verify that plunger rod (14) is inside the shift lever guide. The shift lever guide is located inside shift lever housing (13).

2. Reinstall three mounting screws (5). Apply the following torque to the mounting screws:

   Note: Some solenoids will have four mounting screws on the base of the solenoid.

   • 14.12 N·m (125 lb in) to 21.47 N·m (190 lb in)

3. Install a new 1/2 inch plunger nut (12). Finger tighten the plunger nut.

4. Check pinion clearance. Refer to Illustration 6.

   Note: To avoid personal injury and property damage, take proper care when completing this step. To avoid overheating and possible starting motor damage, maintain power for no longer than 1 minute on Step 4.a before the solenoid is allowed to cool.

   1. For 12 V solenoids, apply 12 DCV to the solenoid's secondary winding. For 24 V solenoids, apply 24 DCV to the solenoid's secondary winding.

      • Attach the positive power lead (+) to solenoid switch terminal (8).

      • Attach the negative power lead (−) to solenoid ground terminal (7). For grounded models, apply the negative power lead (−) to the solenoid body.

   2. Depress plunger rod (14) into the access hole. Depressing the plunger rod will seat the plunger closed against the plunger stop.

   3. Check the pinion clearance. Refer to Illustration 6.

      • Measure the distance from the pinions front face to the inside machined surface of the nose housing. This distance must conform to product specification. For 42MT and 50MT models, the product specification is 8.6 mm (0.339 inch) to 9.91 mm (0.390 inch). For 37MT models and 41MT models, the product specification is 0.254 mm (0.01 inch) to 1.778 mm (0.07 inch). If necessary, adjust the distance by adjusting plunger nut (12). 1/2 inch plunger nut is located in shift lever housing (13). To gain access to the plunger nut, remove access plug (11).

   4. When the pinion is properly adjusted, disconnect the power.

5. Reinstall access plug (11) and gasket (3) to the front of the lever housing. Tighten the access plug to a minimum of 8.13 N·m (72 lb in).

6. Reinstall the solenoid to the motor field connector strap (10). Perform Steps 6.a through 6.e.

   1. Reinstall 1/4 inch screw (9) to the motor field terminal. Finger tighten the screw.

   2. For 42MT and 50MT models, reinstall 1/2 inch nut (1) to the solenoid motor terminal. Finger tighten the nut. For 37MT models and 41MT models, reinstall the 1/4 inch screw (2) to the solenoid motor terminal. Finger tighten the screw.

   3. Apply the following torque to the motor field terminal screw (9):

      • 8.5 N·m (75 lb in) to 10.7 N·m (95 lb in)

   4. For 42MT models, apply the following torque to 1/2 inch nut (1):

      • For 12 DCV models, 27.1 N·m (240 lb in) to 33.9 N·m (300 lb in).

      • For 24 DCV models, 20.3 N·m (180 lb in) to 27.1 N·m (240 lb in).

   5. For 37MT models and 41MT models, apply the following torque to 1/4 inch screw (2):

      • 8.5 N·m (75 lb in) to 10.2 N·m (90 lb in)

7. For insulated models, reinstall the solenoid ground lead to the solenoid ground terminal. Reinstall the nut and washer assembly. Apply the following torque to the nut:

   • 1.8 N·m (16 lb in) to 4.3 N·m (38 lb in)

8. Perform the following test in order to ensure that the solenoid is functional.

   1. Set the multimeter to the resistance setting.

   2. Connect the negative multimeter lead to the solenoids ground terminal (7).

   3. Connect the positive multimeter lead to the solenoid motor terminal (1, 2).

   4. If the solenoid is functioning properly, there will be an open circuit between the solenoid ground terminal and the solenoid motor terminal.