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WRX trany swap: do I need rear hubs or hubs and knuckles?

Posted: Sat May 30, 2009 9:41 pm
by baddriver
I have a 1991 turbo Legacy with a bad transmission and I'm getting parts for a WRX transmission swap.

Right now I have:

a complete 2003 WRX transmission assembly
rear diff
rear axles
wrx flywheel
wrx clutch
wrx pressure plate & tob


I want to be able to swap out full WRX rear axles if needed
in the future so to do this do I need the hubs,
will I need anything other than hubs to match the knuckles.

Would there be any issues with me n me keeping the 91 legacy parking brake assembly, knuckles,rotors,, etc and just adding the hubs to what I have for the swap?

Also is there any difference between the stock 1991 LSD unit and a 2003
LSD unit?

I am aware of ratio difference for teh whole differential , but I
am focused on the LSD or VLSD units themselves.

Posted: Sun May 31, 2009 4:13 am
by Legacy777
No, the VLSD's should be the same.

Posted: Mon Jun 01, 2009 3:44 am
by n2x4
You don't need to replace anything to get the WRX driveline to bolt up. WRX axles will fit in place of the Legacy axles just fine. No hub/knuckle swaps required.

You have all the parts you'd need to do the swap now. The only thing you'll need to change is the pinion flange on the rear diff if you plan to reuse the Legacy driveshaft. The bolt spacing is a bit different between new and old styles. No big deal to swap though.

Posted: Fri Sep 11, 2009 3:26 am
by nicv217
n2x4 wrote:You don't need to replace anything to get the WRX driveline to bolt up. WRX axles will fit in place of the Legacy axles just fine. No hub/knuckle swaps required.

You have all the parts you'd need to do the swap now. The only thing you'll need to change is the pinion flange on the rear diff if you plan to reuse the Legacy driveshaft. The bolt spacing is a bit different between new and old styles. No big deal to swap though.
this sounds stupid but how do you change the pinion flange on the diff in the future i will be doing this swap

Posted: Fri Sep 11, 2009 6:12 am
by roundeye
with the driveshaft out, remove the nut recessed in the center of the flange, pull the flange off (tap gently w/ a hammer if necessary), put the new one on, and torque to 123-145lb-ft.

Posted: Wed Sep 16, 2009 4:38 am
by nicv217
thanks very much

Posted: Tue Sep 29, 2009 7:16 pm
by race_to_live
i also have a bad trans in the 91 and would like a trans that would hold a bit more power. i have been thinking about doing some kind of wrx tranny swap but i don't know what to get. do i just need a wrx tranny, the clutch and flywheel kit, and the pinion flange off the wrx rear diff, to just bolt on?

Posted: Wed Sep 30, 2009 7:07 pm
by race_to_live
what about all the electrical stuff? the neutral and reverse switches? do they work?