Transfer Case Assembly Replacement TrailBlazer, Envoy

1. Raise the vehicle. Refer to Lifting and Jacking the Vehicle .
2. Remove the fuel tank shield, if equipped. Refer to Fuel Tank Shield Replacement .
3. Remove the rear propeller Shaft. Refer to Rear Propeller Shaft Replacement .
4. Drain the transfer case. Refer to Transfer Case Fluid Replacement .



5. Remove the fuel lines from the retainer.



6. Remove the electrical harness from the retainer (right side).



7. Remove the electrical harness from the retainer (left side).



8. Disconnect the electrical connectors from the speed sensors (front speed sensor shown).
9. Disconnect the motor/encoder electrical connector.



10. Remove the transfer case wiring harness.



11. Disconnect the vent hose.
12. Install a transmission jack for the transfer case.



13. Remove the transfer case adapter (2) to transfer case nuts (5).

Important: While removing the transfer case the front propeller shaft must be disconnected from the transfer case. Refer to Front Propeller Shaft Replacement .

14. Remove the transfer case (3) from the vehicle.

Important: The transfer case gasket may become damaged during the removal procedure.

15. Remove the transfer case gasket (4).

Important: If the transfer case gasket is damaged, replace it. DO NOT use silicone sealant in place or with the transfer case gasket.

Important: While installing the transfer case the front propeller shaft must be connected to the transfer case. Refer to Front Propeller Shaft Replacement .

1. Install or replace the transfer case gasket (4).
2. Install the transfer case (3) in the vehicle.

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.

3. Install the transfer case adapter (2) to transfer case nuts (5). Ensure the fuel line retainer (1) is in place.

Tighten
Tighten the nuts to 47 N·m (35 lb ft).

4. Remove the transmission jack stand.



5. Connect the electrical connectors to the speed sensors (front speed sensor shown).



6. Connect the vent hose.
7. Connect the motor/encoder electrical connector.



8. Install the transfer case harness to the transfer case.



9. Install the transfer case wiring harness to the retainers (left side).



10. Install the transfer case wiring harness to the retainers (right side).



11. Install the fuel lines to the retainer.
12. Install the rear propeller shaft. Refer to Rear Propeller Shaft Replacement .
13. Fill the transfer case with fluid. Refer to Transfer Case Fluid Replacement .
14. Install the fuel tank shield, if equipped. Refer to Fuel Tank Shield Replacement .
15. Lower the vehicle. Refer to Lifting and Jacking the Vehicle .

Transfer Case Assembly Replacement Trailblazer EXT, Envoy XL

1. Raise the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.
2. Remove the transfer case shield, if equipped. Refer to Transfer Case Shield Replacement .
3. Remove the rear propeller Shaft. Refer to Rear Propeller Shaft Replacement in Propeller Shaft.
4. Drain the transfer case. Refer to Transfer Case Fluid Replacement .
5. Remove the front propeller shaft. Refer to Front Propeller Shaft Replacement in Propeller Shaft.



6. Remove the fuel lines from the retainer.



7. Remove the electrical harness from the retainer (right side).



8. Remove the electrical harness from the retainer (left side).



9. Disconnect the electrical connectors from the speed sensors (front speed sensor shown).
10. Disconnect the motor/encoder electrical connector.



11. Remove the transfer case wiring harness.



12. Disconnect the vent hose.
13. Install a transmission jack for the transfer case.



14. Remove the transfer case adapter (2) to transfer case nuts (5).
15. Remove the transfer case (3) from the vehicle.

Important: The transfer case gasket may become damaged during the removal procedure.

16. Remove the transfer case gasket (4).

Important: If the transfer case gasket is damaged, replace it. DO NOT use silicone sealant in place or with the transfer case gasket.

1. Install or replace the transfer case gasket (4).
2. Install the transfer case (3) in the vehicle.

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.

3. Install the transfer case adapter (2) to transfer case nuts (5). Ensure the fuel line retainer (1) is in place.

Tighten
Tighten the nuts to 47 N·m (35 lb ft).

4. Remove the transmission jack stand.



5. Connect the electrical connectors to the speed sensors (front speed sensor shown).



6. Connect the vent hose.
7. Connect the motor/encoder electrical connector.



8. Install the transfer case harness to the transfer case.



9. Install the transfer case wiring harness to the retainers (left side).



10. Install the transfer case wiring harness to the retainers (right side).



11. Install the fuel lines to the retainer.
12. Install the rear propeller shaft. Refer to Rear Propeller Shaft Replacement in Propeller Shaft.
13. Install the front propeller shaft. Refer to Front Propeller Shaft Replacement in Propeller Shaft.
14. Fill the transfer case with fluid. Refer to Transfer Case Fluid Replacement .
15. Install the transfer case shield, if equipped. Refer to Transfer Case Shield Replacement .
16. Lower the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.