Transfer Case Motor/Encoder Replacement

Transfer Case Motor/Encoder Replacement (Trail Blazer, Envoy, Rainier, Bravada)

Removal Procedure

Important: Before the motor encoder is removed, ensure that the motor encoder is in the 2HI position.





1. Raise the vehicle.
2. Remove the fuel tank shield, if equipped.
3. Disconnect the motor encoder electrical connector (1).





4. Remove the motor encoder mounting bolts.





5. Remove the motor encoder assembly.

Important: When replacing the encoder rotary position sensor follow these additional steps. The rotary position sensor is circular with 3 contacts on one side and is positioned behind the motor encoder gasket.

6. Position the motor on a work bench.





7. Release the 4 tabs that retain the motor encoder gasket and remove the gasket (1).
8. Remove the snap ring and washer retaining the motor encoder rotary position sensor.

Important: Gently lift the rotary position sensor and wiring to disconnect it. The internal wires go to a connector within the motor housing. This internal wire connector does not have a locking tab and is easily disturbed.

9. lift the motor encoder rotary position sensor (2) from the motor shaft.
10. Disconnect the rotary position sensor (2) from the wiring harness.

Important: Look at the motor encoder housing (1) where the rotary position sensor was removed from. Take note of the "Hex" in the housing where the new sensor will seat when properly installed.

Installation Procedure

Important: Provided the rotary position sensor was removed, follow steps to install the sensor, otherwise proceed to installing the motor encoder to the transfer case.





1. Connect the wiring harness to the rotary position sensor.
2. Gently insert a suitable tool along side the internal wires and press down on the internal wire connector to insure the connector is fully installed.
3. Properly align the keyway of the rotary position sensor with the motor encoder shaft as indicated by the center reference line shown in the graphic.





4. Ensure that the hex on the rotary position sensor (2) fits in the hex of the motor encoder housing (3).
5. Install the washer and snap ring retaining the motor encoder rotary position sensor.
6. Install the motor encoder gasket (1).






Important: When performing this service procedure, make sure that the motor encoder unit is fiat against the transfer case for proper installation.

7. Install the motor encoder to the transfer case.






Notice: Refer to Fastener Notice in Cautions and Notices.

8. Install motor, encoder mounting bolts to the transfer case.
^ Tighten the bolts to 16 Nm (12 ft. lbs.).





9. Connect the motor encoder electrical connector (1).
10. Install the fuel tank shield, if equipped.
11. Lower the vehicle.