GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2009 🢒 Sierra Denali 🢒 Diagnostic Navigation 🢒 Vehicle Diagnostic Information 🢒 Four-Wheel Drive Does Not Engage

Important: Before performing the following diagnostic procedure, ensure that all electrical diagnostic procedures have been performed and there are no DTCs.

Step

Action

Yes

No

1

Confirm operation of system. Refer to Diagnostic Starting Point - Front Drive Axle .

Is the system operating properly?

Test the system

Go to Step 2

2

  1. Raise the vehicle. Refer to Lifting and Jacking the Vehicle .
  2. Remove the actuator motor. Refer to Front Drive Axle Actuator Replacement .
  3. Using a brass drift, apply pressure to the clutch fork.
  4. Turn the right wheel to align the clutch gears.

While turning the right wheel, does the left wheel turn in the opposite direction?

Test the system

Go to Step 3

3
  1. Remove the inner axle shaft and housing assembly. Refer to Front Drive Axle Inner Shaft and Inner Shaft Housing Replacement .
  2. Inspect the following:
    3. • Clutch Fork
    • Clutch Sleeve
    • Clutch Gear
    • Clutch Return Spring
    • Repair as needed.

Did you complete the repair?

Test the system

System OK