I was told by a reputable mechanic that swapping out gears with used ones is a bad deal. He said they will never "run in" correctly again. Does anyone have any experience with this? I want to swap my stock 3:21's for 3:73's. Thanks for the input in advance!

 

I've heard the same thing just this weekend actually. New gears are cheap enough to buy new, especially if you buy the front/rear package. Northridge 4x4 has the complete Yukon front/rear set with install kit for $445.

 

I have swapped in used 4.10 gears. They had around 20,000 miles on them. No problems with them at all. I put around 10,000 more miles on the so far. I had 3.21 gears so I had to change them when I got the 35s on.

 

Thanks for that idea. I think I'll check Northridge out!

 

Was wandering what your rpms are shaggy after swapping in the 4.10s. Was thinking I might go 4.56 if possible