What to replace when replacing Diff
 

Hi! I have a 86 sport model rx7. I have located an Lsd to replace my open diff. When i make the swap what new parts should i get? I also want to get a suspension bushing kit is there any thing in that kit that i can install with the diff out? Thank you!

Are you replacing the differential itself or swapping entire diff assemblies (casing)?

If its the differential itself that you're swapping into your case, you'll wanna get new side seals & you'll need backlash and preload set accordingly. If you feel the need, you can have the diff rebuilt using mazda comp parts & replace the diff bearings. But thats really it as far as that.

if its just the casings, check out the rear & front mounts.

I might be changing the whole casing it self. But is it easier to just change the diff it self? If so how do you set the back lash? The rear diff mount is the mounts in the hanger right? Also will a stiffer front diff help with any thing? Again is there any thing in the Poly suspension that goes on to the diff? Thanks!

I might be changing the whole casing it self. But is it easier to just change the diff it self? If so how do you set the back lash? The rear diff mount is the mounts in the hanger right? Also will a stiffer front diff help with any thing? Again is there any thing in the Poly suspension that goes on to the diff? Thanks!

as heavy as the diff. and mounts are together, it's going to be much easier to swap the entire diff assembly than the gear sets, if you have a set of extra hands to help you out as that thing can be pretty heavy. the bushings that come with the suspension setup will not have nothing to do with the diff bushings. i believe you must buy those separately. mazdatrix carries mazdacomp bushings but they're expensive. the stiffer front diff mount will help prevent wheel hop to an extent, and is simply a stronger replacement for the stocker which tears often. one recomendation i have though, soak the shit out of every bolt you plan to remove with some kind of thread loosening spray (is prefer PB blaster, or whatever the hell it's called) the night before you undergo the swap. it will make things much easier.

Needs to be taken to shop primarily but you need the tool which is used specifically for measuring it.

just replace the assembly...simple!