GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2003 🢒 TopKick C-Series (Crew) C6/C7/C8 🢒 Driveline/Axle 🢒 Rear Axle Controls 🢒 Differential Lock Switch Replacement

Removal Procedure
  1. Apply the parking brake.
  2. Block the vehicle wheels.
  3. Drain all of the air reservoirs. Refer to Draining Reservoirs in Air Brakes.

    4. Object Number: 203047 Size: MH

    Important: Tag the air lines for later installation.

  4. Remove the air lines at the differential lock control valve. Refer to Hose and Line Replacement - Nylon Push-In Type Fitting in Air Brakes.

    5. Object Number: 203048 Size: SH
  5. Disconnect the wiring harness connector.
  6. Remove the following components from the differential lock control valve:
    7. • The nuts
    • The washers
    • The bolts
    • The differential lock control valve

Installation Procedure
  1. Install the differential lock control valve.

    2. Notice: Refer to Fastener Notice in the Preface section.

  2. Install the following components to the differential lock control valve:
    3. • The bolts
    • The washers
    • The nuts

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


    Object Number: 203048 Size: SH
  3. Connect the wiring harness connector.

    4. Object Number: 203047 Size: MH
  4. Install the air lines at the differential lock control valve. Refer to Hose and Line Replacement - Nylon Push-In Type Fitting in Air Brakes.
  5. Start the engine.
  6. Inspect for air leaks. Refer to Air Brake System Testing in Air Brakes.
  7. Verify proper operation of the inter-axle differential lock.
  8. Remove the wheel blocks.