Two Speed Rear Axle Shift Motor Replacement HPZ

1. Apply the parking brake.
2. Block the wheels.
3. Shift the two-speed rear axle shift switch to the LOW range.



4. Remove the two-speed rear axle wiring harness clip nut (1).
5. Remove the two-speed rear axle wiring harness clip (2) from the stud.



6. Disconnect the two-speed rear axle wiring harness connector.



7. Remove the two-speed rear axle shift motor nuts (1) and the washers (2).
8. Remove the two-speed rear axle shift motor (6).
9. Remove the two-speed rear axle spring from the two speed rear axle shift fork (4).
10. Remove the two-speed rear axle shift fork seal (5) from the differential carrier housing (3).

1. Install the two-speed rear axle shift fork seal (5) onto the differential carrier housing (3).
2. Install the two-speed rear axle shift fork spring onto the shift fork (4).



3. Apply a thin coat of rear axle lubricant to the shift fork and the two-speed rear axle shift motor lever. Refer to Fluid and Lubricant Recommendations in General Information.




Important: Ensure that the two-speed rear axle shift motor lever engages with the two-speed rear axle shift fork (4).

4. Install the two-speed rear axle shift motor (6).

Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

5. Install the two-speed rear axle shift motor washers (2) and the nuts (1).

Tighten
Tighten the nuts (1) to 74 N·m (55 lb ft).




6. Connect the two-speed rear axle wiring harness connector.



7. Install the two-speed rear axle wiring harness clip (2) onto the stud.
8. Install the two-speed rear axle wiring harness clip nut (1).

Tighten
Tighten the nut (1) to 1.9 N·m (17 lb in).

9. Turn the ignition switch to the ON position.
10. Verify proper operation of the two-speed rear axle.
11. Remove the wheel blocks.

Two Speed Rear Axle Shift Motor Replacement HR2

1. Apply the parking brake.
2. Block the wheels.
3. Shift the two-speed rear axle shift control valve to the LOW range.
4. Drain all of the air reservoirs. Refer to Draining Reservoirs in Air Brakes.
5. Remove the air line at the two-speed rear axle shift motor. Refer to Hose and Line Replacement - Nylon and Metal Compression in Air Brakes.
6. Remove the two-speed rear axle shift motor mounting stud nuts (1) and the washers (2).
7. Remove the two-speed rear axle shift motor (3).
8. Remove the two-speed rear axle spring (7) from the two-speed rear axle shift fork (5).
9. Remove the two-speed rear axle shift fork seal (6) from the differential carrier housing (4).
10. Inspect the air lines for the following conditions:

•

Damage

•

Kinks

•

Wear

11. Repair or replace the air lines as needed. Refer to Hose and Line Replacement - Nylon and Metal Compression in Air Brakes.

1. Install the two-speed rear axle shift fork seal (6) onto the differential carrier housing (4).
2. Install the two-speed rear axle spring (7) onto the two-speed rear axle shift fork (5).



3. Apply a thin coat of rear axle lubricant to the shift fork and the two-speed rear axle shift motor lever. Refer to Fluid and Lubricant Recommendations in General Information.




Important: Ensure that the two-speed rear axle shift motor lever engages with the two-speed rear axle shift fork (5).

4. Install the two-speed rear axle shift motor (3).

Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

5. Install the two-speed rear axle shift motor washers (2) and the nuts (1).

Tighten
Tighten the two-speed rear axle shift motor nuts (1) to 74 N·m (55 lb ft).




6. Fill the two-speed rear axle motor with lubricant. Refer to Fluid and Lubricant Recommendations in General Information.

6.1.	Remove the two-speed rear axle shift motor pipe plug (1) from the two-speed rear axle shift motor filler hole.

6.2.	Fill the two-speed rear axle shift motor with lubricant.

6.3.	Ensure that the two-speed rear axle shift motor lubricant is level with the bottom of the two-speed rear axle shift motor filler hole.

6.4.	Install the two-speed rear axle shift motor pipe plug (1) into the two-speed rear axle shift motor filler hole.

Tighten
Tighten the two-speed rear axle shift motor pipe plug (1) to 13 N·m (115 lb ft).

7. Install the air line at the two-speed rear axle shift motor. Refer to Hose and Line Replacement - Nylon and Metal Compression in Air Brakes.
8. Start the engine. Charge the system to the air compressor governor cutout point.
9. Stop the engine.
10. Inspect for air leaks using a soap solution.
11. Verify proper operation of the two-speed rear axle.
12. Remove the wheel blocks.