2004 Yukon vibration type noise on decel and acceleration I have a vibration type noise when slowing down below 20 mph and it goes away when i shift into neutral. It almost sound like a cupped tire type of road noise. I installed brand new tires 100 miles ago. The old tires were cupped. I also hear a whining noise when I maintain a slow speed and bring engine rpm up from coast to very slight acceleration. Seems to be a front differential type of noise that you'd hear in the rear diff between the ring and pinion gears. Could this noise be transfer case related?