New to forum, hope someone can help. I have a 1996 GMC Suburban 1500, 2 1/2 ton, front wheel drive with 220,000 miles, rebuilt engine. Did stupid thing by driving vehicle for extended time with whirring noise at rear end. Now, whirring noise is gone and replaced by clunking noise. Tranny mount was recently replaced and tranny was shifting fine before clunking noise started. Could it be the rear diff or rear wheel bearing and/or if it is the wheel bearing, is it hard to replace/repair?