2004 V8 5.3 with AWD and 68,000 miles. When making tight turn say in a parking lot, the rear end act like its crabbing or jumping. I had the identical vehicle before and that had a very smooth turning action.
Rear differential crabbing or binding? on 2004 Buick Rainier
Look at the tires that they are the same size make and thread depth. Get the differential oil hot by doing figure eights in a parking lot change the oil and use GM/Buick approved oil in the differential.