i have three different rear ends. 2 are from camaros and one of them has a posi...the rear end i have in the car has 2.73 and the one with the posi has 3.23......i also hav a rear outta 83 chevy... same type of rear 10 bolt 8.5 "...it has 3.42..i want to put the posi from theone and the 3.42 from the other in my car...i was wondering if all the rears will have the same amount of shims or is there a way to shim itby myself im sorry if my post is a bit confusing thanx for bearing with me

 

Each rear end requires it's own setup. Gears and posi has nothing to do with it. For example: lets say you have two 79 Camaro 8.5 diffs, both posi, both 3.42 gears. One might take a .025" pinion shim, the other .027". Same on the side carrier shims. The shims are to account for the differences in how the diff housing was machined.

The pinion shim that's in the diff you want to install the gears in is usually a good starting point, and will work 70% of the time. Side shims are easier to change, so that's not as big a deal as the pinion shim. Doing a diff isn't easy the first time around if you don't have the right tools and someone to show you how. My first gear change took two weeks. But after that it's not that hard, especially after you learn not to use the crush collar. I showed my nephew how to do a gear swap, and now he knocks them off in his driveway. Most are for his 5.0 buddies.

So unless it's for your daily driver and you can't have it out of service for long, dive in and give it a shot.

 

why don't i want to use the crush sleeve...what would i use instead.....do i have to use the special tools to do this and how do u know when the pinion is spaced far enough out???? i'm sorry if these are stupid questions i don't know anything about a rear end except the bits i can find in service manuals thanx