Four wheel drive will not engage

Hi,

There is an electric actuator on the front axle that may not be working. What I suggest is to remove it and then have a helper shift to 4wd while you watch if it is working.

Here are the directions for replacement. You can use them for removal and install for testing. The attached pics correlate with the directions.

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2001 Chevy Truck K 1500 Truck 4WD V8-5.3L VIN T
Electric Motor Actuator Replacement
Vehicle Transmission and Drivetrain Differential Assembly Service and Repair Procedures Front Drive Axle Electric Motor Actuator Replacement
ELECTRIC MOTOR ACTUATOR REPLACEMENT
Electric Motor Actuator Replacement
Removal Procedure

pic 1

1. Raise the vehicle. Refer to Vehicle Lifting.
2. Remove the front differential carrier shield (if equipped).
3. Disconnect the electrical connector from the actuator (3).
4. Remove the electric motor actuator (3) by turning the actuator counterclockwise.

Installation Procedure

pic 2

1. Apply sealant (GM P/N 12346004 or equivalent) to the threads of the electric motor actuator.

Notice: Refer to Fastener Notice in Service Precautions.

2. Install the electric motor actuator (3).
Tighten the actuator to 20 Nm (15 ft. Lbs.).
3. Connect the electrical connector to the actuator.
4. Install the front differential carrier shield (if equipped).
5. Lower the vehicle.

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Let me know if this helps or if you have other questions.

Take care and God Bless,

Joe

Hi,

You are very welcome. If you have a chance, let me know what you find or if you have other questions.

Take care,
Joe

John,

When you shift, you indicated hearing the actuator. Does it sound like it always has? The actuator may not be working. Also, was there any noise that could be indicating an internal problem? Unless these transfer cases are abused, they usually hold up really well.

Let me know.

Take care and God Bless,

Joe

At this point, the only thing I can think of is to pull the actuator and see if it is moving. You may hear it trying, but it may not be actually working properly. The idea that the front axle locks in points back to the transfer case. If there is nothing making noise when driving, I don't think it's internal. That leaves the actuator.

Joe