Front Drive Axle (8.25 S4WD and 9.25 Axles)

Inner Shaft and/or Housing Replacement - Front Drive Axle (8.25 S4WD and 9.25 Axles)

Removal Procedure





1. Raise the vehicle. Refer to Lifting and Jacking the Vehicle.
2. Drain the differential carrier assembly. Refer to Lubricant Replacement - Front Drive Axle.
3. Disconnect the electrical connector from the electric motor actuator.





4. Disconnect the wire harness from the inner axle shaft housing.
5. Remove the stabilizer shaft link assembly. Refer to Stabilizer Shaft Link Replacement in Front Suspension.





6. Remove the wheel drive shaft inboard flange bolts from the inner axle shaft.
Disconnect the wheel drive shaft from the inner axle shaft.





7. Remove the inner axle shaft housing nuts from the bracket.





8. For 25/35 series vehicles, perform the following steps in order to provide additional clearance so the inner axle housing can be removed from the vehicle:
8.1. Remove the front axle mounting bracket to frame nuts.
8.2. Slide the front axle mounting bracket towards the engine. It may be necessary to pull down on the inner axle housing and/or push up on the mounting bracket in order to gain clearance.





9. Remove the inner axle shaft housing bolts from the differential carrier case.





Important: Keep the open end of the inner axle shaft housing up.

10. Carefully remove the inner axle shaft housing assembly from the differential carrier assembly.





11. For the 8.25 inch axle, remove the following components from the inner axle shaft housing:
11.1. The clutch fork inner spring (10)
11.2. The clutch fork assembly (11)
11.3. The clutch shaft shim (9)
11.4. The clutch sleeve (8)
11.5. The clutch gear (6) by doing the following:
11.5.1. Clamp the inner axle shaft housing (4) in a vise.
Clamp only on the mounting flange.
11.5.2. Strike the inside surface of the shaft (1) flange with a hammer and a brass drift in order to dislodge the front drive axle clutch gear (6) from the inner axle shaft (1).
11.6. The thrust washer (5)





12. For the 9.25 inch axle, remove the following components from the inner axle shaft housing:
12.1. The clutch fork inner spring (10)
12.2. The clutch fork assembly (11)
12.3. The clutch shaft shim (9)
12.4. The clutch sleeve (8)
12.5. The retainer ring (7)
12.6. The thrust washers (5, 6)





13. Remove the inner axle shaft (2). Tap out the inner axle shaft with a soft-faced mallet.
14. Remove the inner axle seal and the bearing from the axle housing. Refer to Inner Axle Seal and/or Bearing Replacement - Front Drive Axle.

Installation Procedure





1. Install the new inner axle shaft bearing and the seal to the axle housing. Refer to Inner Axle Seal and/or Bearing Replacement - Front Drive Axle.
2. Install the inner axle shaft (2) into the inner axle shaft housing (1).
Carefully tap the inner axle shaft into place with a soft-faced mallet.





3. For the 8.25 inch axle, install the following components into the inner axle shaft housing:

Important: Use chassis grease in order to hold the thrust washer in place.

3.1. The thrust washer (5)
Ensure the tabs on the thrust washer are aligned with the slots in the inner axle shaft housing (4).
3.2. The retainer ring (7) into the clutch gear (6).
3.3. The clutch gear (6) onto the inner axle shaft (1). Drive the clutch gear into place with a plastic hammer.
3.4. Determine the clutch gear shim thickness. Refer to Inner Axle Shaft Shim Adjustment.
3.5. The clutch gear shim (9)
3.6. The clutch sleeve (8)
3.7. The clutch fork assembly (11)
3.8. The clutch fork inner spring (10) into the differential carrier case.





4. For the 9.25 inch axle, install the following components into the inner axle shaft housing:

Important: Use chassis grease in order to hold the thrust washer in place.

4.1. The thrust washer (5) Ensure the tabs on the thrust washer are aligned with the slots in the inner axle shaft housing (4).
4.2. The second thrust washer (6)
4.3. The retainer ring (7) onto the inner axle shaft (1).
4.4. Determine the clutch gear shim thickness. Refer to Inner Axle Shaft Shim Adjustment.
4.5. The clutch gear shim (9)
4.6. The clutch sleeve (8)
4.7. The clutch fork assembly (11)
4.8. The clutch fork inner spring (10) into the differential carrier case.
5. Apply sealant GM P/N 1052942 (Canadian P/N 10953466) or equivalent to the inner axle housing to differential carrier sealing surface.





6. Install the inner axle shaft housing assembly to the differential carrier assembly.





Notice: Refer to Fastener Notice in Service Precautions.

7. Install the inner axle shaft housing bolts.
^ Tighten the inner axle shaft housing bolts to 40 Nm (30 ft. lbs.).





8. For 25/35 series vehicles, perform the following steps in order to install the front axle mounting bracket to the inner axle shaft housing:
8.1. Slide the front axle mounting bracket towards the frame. Install the front axle mounting bracket studs into the inner shaft housing mounting flange. It may be necessary to push up on the front axle mounting bracket and/or pull down on the inner axle housing in order to gain enough clearance to install the mounting bracket studs into the inner shaft housing.
8.2. Install the front axle mounting bracket to frame nuts.
^ Tighten the inner axle shaft housing mounting bracket to frame nuts to 90 Nm (67 ft. lbs.).





9. Install the inner axle shaft housing washers and nuts to the bracket.
^ Tighten the inner axle shaft housing nuts to 100 Nm (75 ft. lbs.).
10. Connect the wheel drive shaft inboard flange to the inner axle shaft.





11. Install the wheel drive shaft inboard flange to the inner axle shaft bolts.
^ Tighten the wheel drive shaft inboard flange to inner axle shaft bolts to 79 Nm (58 ft. lbs.).
12. Install the stabilizer shaft link assembly. Refer to Stabilizer Shaft Link Replacement in Front Suspension.





13. Connect the wire harness to the inner axle shaft housing.





14. Connect the electrical connector to the front axle actuator.
15. Fill the differential carrier assembly with axle lubricant. Use the proper fluid. Refer to Lubricant Replacement - Front Drive Axle.
16. Lower the vehicle.