The biggest problem has nothing to do with set-up in my case....trust me....it's in the machining of the gear. We spent over 3 hours playing with pinion depth and carrier shims.....the pattern was never perfect on my Superior 4.56s. 9 out of 10 attempts left the coast side with a poor pattern. You can only change the set-up so much to alter the pattern, and we altered it as much as possible. Besides me contributing, the work was done by Lamotta Performance.....a mustang shop who has probably done 5000+ gear sets in Ford rear-ends over the last 8 years. They know their diffs. When we threw in the Ford 4.10 gear set, both coast and acceleration patterns were perfect on the first attempt.

Fatherford, your Yukon gears are quiet probably because they are machined better than most aftermarket gears. I went with Yukon's up front since Ford discontinued their reverse rotation 4.10s....they set up very decently. Not as nice as the Ford gears in the back, but much better than the Superior set that I was replacing. When I did the 4.56s, I went with Precision up front and they had a decent pattern as well. So maybe not all aftermarket gear sets are trash, but the Superiors I went with were!!

 

I got ford racing 4.10... Very smooth.... very quiet...

If I listen REAL hard, I can barely hear em.