i was thinking the same thing, that the front diff isnt disengaging. what do you suggest? take the diff apart? or just where the acuator cable goes in? i have a dealership diagram of the front diff so that should help. but i need to fix it soon. also, would a steering stabilizer help? i see that on the crossmember there is a mount for it.

 

Guys, I have been experiancing the same symptoms as listed above. It felt like the truck was stuck in 4x4 when turning slow in parking lots ect. i was looking thru my maintenance records and realized that i had three things over due. 1) My transfer case fluid was changed at 15k, 36k, and never again. So it has 130k on that fluid. The fuel filter is about the same, and the rear diff had about 50 k on it. I replaced the fuel filter, transfer case fluid with GM Autotrak, and M1 75w90 in the rear diff. Truck is fixed and i no longer that that shake/shudder in parking lots ect. Im not sure which one fixed it but any are lacking on your maintenance schedule maybe try it.