I came in knowing the problem with my 2004 Grand Cherokee was a noisy rear differential. Got a fair price quote for the labor to replace the ring and pinion gears and decided to go with it. Anthony got it apart and told me I needed a number of bearings in addition to the ring & pinion gears that I brought with me. The work took longer than I expected, but I was OK with that. He patiently showed me some of the worn parts when I picked it up. The additional bearings they installed seemed quite expensive but I can't argue with the results -- The differential is smooth and quiet now.