I have tried to follow all this, now I have a question. When you look at the spindle, is it smooth where the bearing rides? Are there any grooves or signs that the bearing may be turning on the spindle?
Since you have changed bearings around, and the noise still comes back, it's not the bearing it self. The bearing could be rotating on the spindle though. I would not think that it would do it when you turn it by hand though.
I am trying to remember what year GM went to ABS on the 88-98 trucks. Did your old rotor have a ring on the back side near the center that had teeth on it? Does the new one?
If your old rotor was non-ABS without the toothed ring, and the new rotor had the ABS ring on it, it's posible that it could be rubbing something. Maybe one of the bolt heads for the backing plate?????
Just making guesses here. Let us know what you find out....
