Spent all day today setting p the new Motive ring and pinion in the Dana 30. I hate that they use shims instead of crush sleeve. Anyways, I know Nordy had issues with the Motive gears in his car but mine are perfectly quiet. I found that they prerun them and stamp the install depth on the pinion gear. Mine said the depth was 2.261 and I ended up at 2.256 which was as close as I could get with the shims I had. I also set the bearing preload at 23 in/lbs and the backlash at .009. Here's why the old one was causing a vibration. It broke another tooth from the last time I looked at it.