http://www.z1motorsports.com/350_g35...oducts_id=4523 this is a link to the install kit I had him install with....

I got it back today. It's a little quieter. The gears I had him install were used and he showed me a picture of when they were out had quite a bit of wear. When I got them you couldn't see it as much because they were a little dirty, then after being installed for a day and getting rubbed around with the oil you could really see the wear.... basically he claimed they are making noise because of the previous wear.

 

He said there would have been metal shavings when he drained it and there wasn't... so the guy I bought them from used screwed me?

 

pix of the wear, pix of contact pattern, pix of backlash measurement, pix of preload measurement. Unless we have all of that information, we won't know.

I've had my gears installed by two different shops on two separate occasions using brand new hardware. Both times, they hummed/whined on any sort of acceleration. I broke the diff down each time to look at the contact pattern. Both times, they were high on the drive heel with no contact seen on the coast side (even with load applied). I am thinking this is improper pinion height.

I took apart the entire differential and measured the pinion shim to be 3.14. I've since bought 4 sizes up from nissan (3.17, 3.20, 3.23, 3.26 ). I plan on putting everything back together myself. Forget performance shops, im doing this myself!

http://www.pirate4x4.com/articles/te...sta/Gear_Setup