I have a bad vibration coming from the rear of my blazer. I also notice a squeak that increases with speed. The vibration starts at 35mph and just gets worse the faster I go.Could this be a wheel bearing? I also have a 12 bolt rearend with a gov-lock and I wandered if it nroke a tooth or something if this would cause this problem. The truck is all stock with 33's. Whatever it is it only happens when I accelerate, not when I'm coasting down a hill.