4x4 High makes grinding noise and pulls left

[rphill1]

I own a 2005 Z71 Avalanche 1500 with 125K miles that I've had since new. When I engaged the four wheel drive high, it has an a loud grinding noise and pulls to the left on dry pavement. When I drive over ice or snow, the noise and pulling immediatly stops. This truck has the 2wd/Auto 4wd option and it has always been driven in 2wd only.

Any guidance or suggestions is appreciated.

[jdmccright]

Sounds like the left hub of the front axle isn't fully locked up. Check the front 4wd actuator. I don't know if it is vacuum-actuated like the older trucks or via solenoid.

If vacuum, check the vacuum actuator's diaphragm for holes and vacuum lines for leaks. If solenoid, check for poor electrical contact and grounds.

Hope this helps!