I have a 99 Silverado 4x4. If I am making a turn in either direction in 2 hi at very slow speeds i.e 5 mph or less the front wheels drag like its a posi trac. If I go over 5 or so mph it does not do this. On occasion when this happens i get a loud clunk from the front drive train. I have removed and checked the front differential motor to make sure it is retracting. It does. When I put the truck on jack stands both tires turn when I turn them. If I try to hold one and turn the other it is very difficult to turn. This does not happen in reverse. Any insight on this would be appreciated. Thanks in advance.

 

i had the same problem and the clunk got real bad. i was worried about the diff too, but was told to first lube the steering shaft just incase (very inexpensive). havent hade a prob since.

 

I had the same problem with my 2003 Silverado. Fortunately it was still under warranty and the dealer lubed the steering shaft; it works great now. Chevy knows about the problem.