I HAVE 2008 SILVERADO 2500 HD,I PUT IT IN FOUR WHEEL THIS WINTER AND HEARD A CLUNK,NOW 4X4 NOT WORKING,THE FRONT DRIVE SHAFT SPINS WITH VEHICLE JACKED UP BUT FRONT AXLE NOT ENGAGING,pULLED THE ACTUATOR MOTOR AND IT LOOKS FINE,HOW DO YOU TELL IF ACTUATOR IS WORKING,thx,don

 

If you have the electric shift then when jacked up you need the ignition switch to run not started. Engage the 4x4 hi button, light should be steady on the button. If the front drive engages the front wheels will lock and not be able to turn. If the light on button does not stay steady then the problem could be shift motor, front acuator or the 4x4 module. The front acuator is a rod that pushes against the shift forks in the front differental when on. Best to find a mechanic that can scan for faults in the 4x4 system. Also there are grounds that may need cleaning. The major one is under the drivers door on the frame rail looking forward.

 

thank you for the feedback,i have a manual floor mounted shifter,