After getting my '99 Impreza 2.5RS stuck numerous times (hey, AWD never gets stuck, right?) even with brand new snow tires on all 4 wheels this winter and noticing to my dismay that only 2 wheels spin when I give it gas on ice (not to mention the fact that if it gets pulled into slush when I am driving, giving it gas will make the car pull harder into the slush and get even more stuck) I have decided that I need a limited slip viscous coupling rear differential, such as is used in the 2000+ year models (I'm assuming that this would help a lot if my car is stuck on ice but not bottomed out, is that a correct assumption?). So the question is; does anyone know where I can buy one from cheap? I know some junkyards are supposed to carry them but that is not the case around here; how about an used parts store that sells them online; anybody know of one?
Thanks. Any tips on this conversion would also be very appreciated :)

car-part.com


-Jay Storm

you will need the axels too if you do this
the output shaft on the differnterials are differnt on SOME of the LSDs

http://wac.addr.com/auto/obs/lsd/lsd.html

Thanks! Appearently if I can find the LSD of a 2000+ Impreza RS it will fit right in without any other mods... That's what I need :)

no
the axels are differnt
the 99 RS diff has female output shafts
the 2000-2001 rs diff has male output shafts

<-- also looking for a 4.11 lsd

this is a diff with male output shafts it happens to be an non lsd version tho :(
http://home.velocitus.net/jaredw/images/Mvc01927.jpg

Ummm... The link above says it'll fit: If you're lucky, the LSD unit will be a drop-in replacement for the open unit in your car. For example, an LSD from a 2000 2.5RS will swap directly into a 1998 2.5RS without any other changes.
I suppose then I would need the differential and the axles? Isn't there a LSD that will bolt right on t my '99 RS?
Damn, this looks like it will be expensive...

You could always get a phantom grip LSD. I think they have been used with success in rally racing and Sport and compact car has used them in some project cars.

There was this auction to:

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&rd=1&category=33731&item=2474651767&sspagename=STRK%3AMEBWA%3AIT

It's make me wonder if we could use any LSD. I mean if all the ring gears match up and the diff is a R160 which just about all suby diffs are maybe the internals are interchangable?

This would get rid of the problem of trying to find a matching LSD with the right gear ratio.

Any thoughts?

-Cybin

hmm that link sure looks like an open diff .. it not a viscus

If your refering to the ebay ad, its not a viscus. In fact I'm not really sure subaru has made a viscus LSD. All the ones I've seen are mechanical LSD's.

-Cybin

there are only two type of lsd sold in NA
1. clutch type r180 in the usdm sti
2. viscus r-160 (in the various imprezas, legacys and foresters)




actually there might be a third
the svx had a viscus r-180

Jaxx, after looking around you are right. Subaru makes a viscus and clutch type center and rear diff. I guess I was hoping for a mechanical type unit like quaife sells. Wonder if the guy selling the diff. knows or cares that it might not be a LSD.

Regardless, if the internals end up being interchangable this would solve the gear ratio problems. It would be a big help for me with a 3.90 gear ratio, the only LSD with that ratio in the turbo legacy.

Here is what I did to get a LSD. First, I took out a cheap clutch type LSD unit from a 1987 3.90 ratio LSD. It came from a Subaru RX, but it was also in some Nissan models like the Datsun 510. Then because the LSD unit used 12mm bolts and my diff used 11mm bolts, I took it to a machine shop where they drilled out my original to accept the 12mm bolts.

Works well and I have been driving the car since, about 10,000 miles. The LSD needs replacing and I am thinking of a torsen type. Is there any reason you guys know of this could not be done on a standard open 4.111 R-160 Hatachi diff?

Mike McBride