37000 miles, only been put into 4 wheel drive once. Just to test. There is a roaring noise while turning left or right at slow speed, (in parking lot or pulling out driveway) but clears when the Yukon is straightened up. It sounds like a hard rub but this has all been cleared. Of note, I activated the 4 wheel drive and drove about 50 yrds, put back in 2 wheel drive and the roaring is gone. If the yukon sits for more than an hour, the noise comes right back. No dealerships have heard of this issue and have no idea what to do. Thanks in advance