Legacy rear diff internals in a WRX case...

[shemoves]

Alright, have a bit of a 'situation.' A friend of mine has a WRX with a 3.9 STi 6mt. He needs a 3.9 rear. I have the stock rear diff out of my '92 SS. He would like to be able to use his thicker WRX axles though. My question is can the internals from a '92 SS rear diff be put inside the case of a WRX rear diff such that he could use his stock rear axles?

[Arctic Assassian]

not happening. The internals are why he couldn't use the axels, not the case.

[shemoves]

what about just swapping out the ring and pinion?

[555BCTurbo]

Why don't you just swap out the stubs...


And I don't think there is really that much of a difference between axles either...as far as strength

[93forestpearl]

Ring and pinion isn't too bad. Just make sure the backlash is correct.

[Blackbart]

Swapping the ring and pinion is the way it is done for the 6 speed swap. I have the instructions on how to set the lash, I can drop them in the mail for you.

[ScottyS]

Anybody have a PDF or tips on backlash settings in the LSD?

I swapped the LSD carrier into a new diff housing and needed to swap the companion flange as well. As a result, I had to take the pinion nut off.

With the correct flange back on, I got the nut right back to where it was before on the shaft, but I wouldn't mind checking the backlash while I have the unit out.

Maybe I'll just have a look at the contact pattern using grease on the ring gear, and call it good if the pattern is all in the center and not biased to heel or toe.

[93forestpearl]

IIRC, the torque spec for the companion flange nut is 134 lb-ft. If you are very experienced in this kind of thing, you can do it by feel. Checking with marker grease is a good idea.