Rear Axle Replacement 15 Series

1. Raise the vehicle. Refer to Lifting and Jacking the Vehicle .
2. Place jack stands or utility stands, such as GMDE 123-B67313, at the front-end of the vehicle.
3. Support the rear axle with jack stands.
4. Remove the tire and wheel assemblies. Refer to Tire and Wheel Removal and Installation .
5. Disconnect the rear axle vent tube.
6. Disconnect the wheel speed sensor connector.
7. Remove the propshaft. Refer to Rear Propeller Shaft Replacement .
8. Disconnect the left-rear park brake cable from the rear axle. Refer to Parking Brake Rear Cable Replacement - Left Side .
9. Disconnect the right-rear park brake cable from the rear axle. Refer to Parking Brake Rear Cable Replacement - Right Side .
10. Remove the caliper assemblies from the rear axle. Refer to Rear Brake Caliper Replacement .
11. Remove the stabilizer shaft from the rear axle. Refer to Stabilizer Shaft Replacement .
12. Remove the crossover brake pipe from the rear axle.
13. Remove the coil springs. Refer to Coil Spring Replacement .
14. Disconnect the track bar from the rear axle. Refer to Rear Axle Tie Rod Replacement .
15. Disconnect the lower control arm from the rear axle. Refer to Rear Axle Lower Control Arm Replacement .
16. Disconnect the upper control arm from the rear axle. Refer to Rear Axle Upper Control Arm Replacement .
17. Remove the rear axle assembly from the vehicle.

1. Install the rear axle assembly to the vehicle.
2. Connect the upper control arm to the rear axle. Refer to Rear Axle Upper Control Arm Replacement .
3. Connect the lower control arm to the rear axle. Refer to Rear Axle Lower Control Arm Replacement .
4. Connect the track bar to the rear axle. Refer to Rear Axle Tie Rod Replacement .
5. Install the coil springs. Refer to Coil Spring Replacement .

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.

6. Install the crossover brake pipe to the rear axle.

Tighten
Tighten the bolt to 22 N·m (16 lb ft).

7. Install the stabilizer shaft to the rear axle. Refer to Stabilizer Shaft Replacement .
8. Install the caliper assemblies to the rear axle. Refer to Rear Brake Caliper Replacement .
9. Connect the right-rear park brake cable to the rear axle. Refer to Parking Brake Rear Cable Replacement - Right Side .
10. Connect the left-rear park brake cable to the rear axle. Refer to Parking Brake Rear Cable Replacement - Left Side .
11. Install the propshaft. Refer to Rear Propeller Shaft Replacement .
12. Connect the wheel speed sensor connector.
13. Connect the rear axle vent tube.
14. Install the tire and wheel assemblies. Refer to Tire and Wheel Removal and Installation .
15. Fill the axle with lubricant. Use the proper fluid. Refer to Approximate Fluid Capacities and to Fluid and Lubricant Recommendations .
16. Remove the utility stands and the jack stands.
17. Lower the vehicle.

Rear Axle Replacement 25 Series w/ RPO NYS

1. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.
2. Place jack stands at the front end of the vehicle in order to support the weight difference when the rear axle is removed.
3. Drain the axle lubricant from the rear axle. Refer to Rear Axle Lubricant Replacement .
4. Remove the propeller shaft. Refer to Rear Propeller Shaft Replacement in Propeller Shaft.
5. Remove the tire and wheel assemblies. Refer to Tire and Wheel Removal and Installation in Tires and Wheels.
6. Disconnect the parking brake cables. Refer to Parking Brake Rear Cable Replacement - Left Side and Parking Brake Rear Cable Replacement - Right Side in Park Brake.
7. Remove the left and right brake calipers from the brake caliper mounting brackets. Do not disconnect the hydraulic brake lines from the brake calipers. Refer to Rear Brake Caliper Replacement in Disc Brakes. Secure the left and the right brake calipers with mechanics wire to the leaf spring or the frame assembly.



8. Remove the 2 flex hose bracket bolts (1).
9. Remove the 2 brake pipe bracket bolts (2).
10. Remove the jounce bracket bolt (3).
11. Remove the brake pipe bracket nut (4). Secure the rear brake pipe assembly with mechanics wire to the under body and frame. Do not bend or kink the brake pipe assembly.
12. Disconnect the shock absorbers from the axle brackets. Refer to Shock Absorber Replacement in Rear Suspension.
13. Remove the vent hose from the rear axle vent fitting. Refer to Vent Hose Replacement .
14. Support the rear axle assembly with a suitable jack. Remove the nuts and the washers if equipped from the U-bolts.
15. Remove the U-bolts, the spring plates and the spacers from the axle assembly.
16. Lower the axle assembly.

1. Place the axle assembly onto the jack and place the rear axle assembly under the vehicle.
2. Align the rear axle assembly with the springs. Using the jack slowly raise the rear axle assembly into position.
3. Connect the spacers, the spring plates and the U-bolts to the rear axle.

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.

4. Install the washers if equipped and the nuts to the U-bolts.

Tighten
Tighten the nuts in a criss cross pattern to 150 N·m (110 lb ft).

5. Install the vent hose to the rear axle vent fitting. Refer to Vent Hose Replacement .
6. Connect the shock absorbers to the rear axle. Refer to Shock Absorber Replacement in Rear Suspension.



7. Remove the mechanics wire supporting the brake pipe assembly. Carefully position the brake pipe assembly onto the rear axle.
8. Install the brake pipe bracket nut (4).

Tighten
Tighten the nut to 13 N·m (115 lb in).

9. Install the jounce bracket bolt (3).

Tighten
Tighten the bolt to 12 N·m (106 lb in).

10. Install the 2 brake pipe bracket bolts (2).

Tighten
Tighten the bolts to 22 N·m (16 lb ft).

11. Install the 2 flex hose bracket bolts (1).

Tighten
Tighten the bolts to 12 N·m (106 lb in).

12. Remove the mechanics wire securing the brake calipers and install the brake calipers to the brake caliper mounting brackets. Refer to Rear Brake Caliper Replacement in Disc Brakes.
13. Connect the parking brake cable. Refer to Parking Brake Rear Cable Replacement - Left Side and Parking Brake Rear Cable Replacement - Right Side in Park Brake.
14. Install the tire and wheel assemblies. Refer to Tire and Wheel Removal and Installation in Tires and Wheels.
15. Connect the propeller shaft. Refer to Rear Propeller Shaft Replacement in Propeller Shaft.
16. Fill the axle with lubricant. Use the proper fluid. Refer to Approximate Fluid Capacities and Fluid and Lubricant Recommendations in Maintenance and Lubrication.
17. Remove the jack stands.
18. Lower the vehicle.

Rear Axle Replacement 25 Series

1. Raise the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.
2. Place jack or utility stands (such as GMDE 123-B67313) at the front end of the vehicle.
3. Drain the axle lubricant from the rear axle. Refer to Rear Axle Lubricant Replacement .
4. Disconnect the propeller shaft. Refer to Rear Propeller Shaft Replacement .
5. Remove the tire and wheel assemblies. Refer to Tire and Wheel Removal and Installation in Tires and Wheels.
6. Disconnect the parking brake cable. Refer to Parking Brake Rear Cable Replacement - Left Side and Parking Brake Rear Cable Replacement - Right Side in Park Brake.
7. Remove the brake line bracket bolts. Suspend the brake lines from the vehicle with heavy mechanics wire.
8. Remove the brake calipers from the brake caliper mounting brackets. Do not disconnect the brake lines. Suspend the calipers from the vehicle with heavy mechanics wire. Refer to Rear Brake Caliper Replacement in Disc Brakes.
9. Disconnect the shock absorbers from the axle brackets. Refer to Shock Absorber Replacement in Rear Suspension.
10. Remove the vent hose from the rear axle vent fitting. Refer to Vent Hose Replacement .
11. Remove the nuts and the washers from the U-bolts.
12. Remove the U-bolts, the spring plates and the spacers form the axle assembly.
13. Lower the axle assembly.

1. Place the rear axle assembly under the vehicle.
2. Align the rear axle assembly with the springs.
3. Connect the spacers, the spring plates and the U-bolts to the rear axle.
4. Raise the rear axle assembly into position.

Notice: Refer to Fastener Notice in the Preface section.

5. Install the washers if equipped and the nuts to the U-bolts.

Tighten

•	For 25 Series Utilities without 8.1 L Engine, tighten the nuts to 72 N·m (53 lb ft).

•	For 25 Series Utilities with 8.1 L Engine, tighten the nuts to 150 N·m (110 lb ft).

6. Install the vent hose to the rear axle vent fitting. Refer to Vent Hose Replacement .
7. Connect the shock absorbers to the rear axle. Refer to Shock Absorber Replacement in Rear Suspension.
8. Install the brake calipers. Refer to Rear Brake Caliper Replacement in Disc Brakes.
9. Install the brake lines and the brake line bracket bolts to the axle.
10. Connect the parking brake cable. Refer to Parking Brake Rear Cable Replacement - Left Side and Parking Brake Rear Cable Replacement - Right Side in Park Brake.
11. Install the tire and wheel assemblies. Refer to Tire and Wheel Removal and Installation in Tires and Wheels.
12. Connect the propeller shaft. Refer to Rear Propeller Shaft Replacement in Propeller Shaft.
13. Fill the axle with lubricant. Use the proper fluid. Refer to Rear Axle Lubricant Replacement .
14. Remove the utility stands.
15. Lower the vehicle.