I had the rear axles out of my 2000 Yukon 1500and was disturbed by the looks of the gears. Both drive and coast sides of ring gear had dull finish over the entire face. There was NO discernable wear pattern and the surface was very smooth to the touch and no groves or any such thing. I expected to see a highly polished surface as i have in the past (15-20 years ago) and I am somewhat concerned about this so my question(s) is/are is this normal and if so what has changed. Oh and I have 120,000 miles on truck, no gear noise and have owned it only two years so can not say for sure if it is original or repaired/replaced. Also not able to get a good look at the pinion gear but appears the same.