Ive always had a whirling/humming sound coming from my rear end area, asked many friends about it and they always said "Man thats just your tires," which i knew it wasnt my tires because i drive it daily and know what my tires sound like. Well after driving with the humming sound for sometime, thing finally got worse. Now im at the point where while driving and slightly turning to the left it sounds rougher and louder like rubbing rubber and now its developed a clunk when engaging gears from park. So i decided to take the diffrential cover off and didnt notice anything abnormal, I replaced the axle bearings thinking that was the issue but the old bearings look fine. So now im assuming it maybe something to do with the pinion. The previous owner installed a leveling kit and added some 20X12 inch rims with 33 in tires, which i feel is part the blame because im sure its still running with the stock 3.42 gears. Any advice would be appreciated.