I have a 2023 Chevrolet 3500 DRW 6.6 Duramax, Crew Cab, 8' bed. 22,000 mi.
We pull a 35' 5th wheel. Approx 14k loaded. After a 3-4 hour pull, 55-65 mph., you pull off the highway, make a 45-90 degree turn, and the rear differential is locked up and chatters BAD.... I have had it to the dealership at 15k for howl, and the same chatter. They found metal and replaced EVERYTHING. Still doing this. Advised the dealer at Oil change. They didn't note any problems? I have read many a forum that advise switching gear oil to aftermarket HP Fluid. Any one have a solution?