I'm doing a 6 Spd swap into my RS. How do i know which legacy rear diff i need? Is there any easy visible way to tell? Can i use my stock rear axles with this diff as well? I'll be using the 6 speed with the wrx auto driveshaft.

TIA!

-b

91-92 Legacy turbo 5MT had a 3.90 final drive and an LSD

You could likely get a non-LSD rear diff from a 93-01 Impreza L 5MT and swap in your LSD unit into it. I saw mention of it in this thread (http://forums.nasioc.com/forums/showthread.php?s=&threadid=537492). Maybe try poking someone from that thread for more info.

are there any aftermarket rear diff's with this ratio?

maybe a kaaz unit which would be a bit stronger?

the diff does not determine the ratio so there are no aftermarket diffs with any ratio.

you buy a new diff, say a kaaz, then you put the correct ring and pinion on. so, say you bought a 93 impreza 3.9 open diff, you could just take that diff out, put the ring gear on the kaaz, and put it back in and you are set.

so, to reiterate, its the ring and pinion that determines final drive, not the diff itself.

try a search, this has all been covered.

Ben

Right i've done a search, but that didn't answer my question. Diffs with the 3.9 final drive, how can i identify them on the outside? Are there any markings on them?

-B

They are all R160. No marking stating what is inside. You can open it and count teeth though.

thanks ebeck.

FYI the ratio for any R160 is stamped on the ring gear, i.e., 39:10 for 3.9 ratio. If in doubt, pull the rear cover and look for this stamped number. No need to count.

Mike McBride

the newer diffs don't have the silver foil sticker listing the ratio like the older ones?

and a gold sticker for LSD?


that's the skinny from the 510 guys
look here: http://kmhafer.datsun510.com/Subaru.htm

Originally posted by gtx510
the newer diffs don't have the silver foil sticker listing the ratio like the older ones?

and a gold sticker for LSD?


that's the skinny from the 510 guys
look here: http://kmhafer.datsun510.com/Subaru.htm



Good info!

annnd ... canadian legacy turbos don't have the lsd ..

If you have serious Horsepower I would get a LSD as the stock diff spider gears are fragile as all hell :huh:

I'm looking believe me.

bump

I just finished my swap. Trust me... buy a diff that already has the 3.90 ring and pinion in it... swapping that stuff out is a total pain in the ass.

amen no-coast-punk,

as i just discovered tonight after already selling one diff because i wanted to be sure i could use stock axles, the guy who sold the kaaz diff to me said it would work with stock axles, but i have now searched after becoming suspicious that it wouldnt and found that it does not work with stock, i have yet to pop them in and check for sure but it doesnt look good. :(

Ben