legacycentral bbs

Got a direct link to the specific post in your build thread with that info?

Added a great pic and description to the first post.

Nice pics!

I have a few unanswered questions and I'm hoping some members might have answers.

is it possible take an open r160 diff, for example 1993 impreza with 4.11fd, and put an LSD unit in ? Will the ring and pinion from an open diff attach correctly to an LSD? Or would the ring and pinion have to be from VLSD, for example , 2001 impreza 2.5rs vlsd 4.11 ...

More specifically im trying to find out if I will have issues with putting a cusco LSD into an open r160 diff. Can i simply use the ring and pinion from the open diff and attach them to LSD unit? Wil i have issues with specific axel fitment?

Is there any physical difference in the carrier units, open and lsd? Is it physically possible to fit the LSD in the OPEN housing?


How much physical difference if any is there between 1990-2001 and 2002-2007 r160 diffs?

An LSD fits in an open case, using the open diff's ring and pinion. You'll have to use a Dremel to grind down a small amount inside the case, or at least I did when I put a vlsd in mine. It'll be obvious where you need to grind when you're trying to put the assembled ring gear+LSD in. As far as axles, most likely you'll have to use the newer style male-to-male axles (from a 2nd gen Legacy)

mike-tracy wrote: As far as axles, most likely you'll have to use the newer style male-to-male axles (from a 2nd gen Legacy)

Ok, so it seems the main issue of axles is different spline count and lengths. This might explain why Cusco lists different parts #'s for different years, I believe I saw 3 different #'s for the GC chassis alone. I think then, in theory, I could fit any of the r160 LSD (1993-2007) options as long as I have proper mating axles.


with the exception of the first gen turbo legacy, Ive only seen Subaru use male to male rear axles.

Yeah, the GC has at least 3 different spline counts. One for the regular r160 diffs, one for the (very rare) r180 diff, and one for the oddball VA-type rear diff, identified by the screw in bearing caps (Normal R160s have bearing caps that are held on by 5 bolts per side)

In order to get the right one with axles that are commonly available, you could order the diff that fits an 02-07 WRX, that is the type that 2nd gen Legacy axles fit.

WRX sedan rear axles have the same spline count as the aforementioned legacy ones, but are different lengths. Can be made to fit if you Force them in, but not worth the hassle, plus reduced life imo.

mike-tracy wrote:
In order to get the right one with axles that are commonly available, you could order the diff that fits an 02-07 WRX, that is the type that 2nd gen Legacy axles fit.

WRX sedan rear axles have the same spline count as the aforementioned legacy ones, but are different lengths. Can be made to fit if you Force them in, but not worth the hassle, plus reduced life imo.

Will any 2nd gen legacy axles work? 1995-1999? Are they all equal lengths? Im coming up with different parts number for left and right, are the spline counts different left to right?

Left and right are interchangeable. Splines are the same between left and right.
There's a slight length difference between left and right for pretty much all rear subaru axles, not enough to cause bad things to happen.

There's probably some wierdo combo of 2nd gen that got the VA2 weaksauce diff with the different splines (I'm thinking the Brighton? maybe). I don't know. If you discover or order axles from an L, LS, LSI, Outback, SUS or GT, you'll get the correct axles.

mike-tracy wrote:All will work, and left and right are interchangeable. Splines are the same.
There's a slight length difference between left and right for pretty much all rear subaru axles, not enough to cause bad things to happen.

interesting... Some of my research is showing a 10mm difference. Thats for the 2nd gen legacy and 2002 wrx.
How much difference are you seeing with the WRX axles?

see my edited comment.

The WRX sedan and STI have widetrack, so ignore those cars & axles. You're making this more complicated than it has to be. So grab 2nd gen Legacy axles, they bolt in to a WRX-compatible diff, and work with your hubs.

mike-tracy wrote:see my edited comment.

The WRX sedan and STI have widetrack, so ignore those cars & axles. You're making this more complicated than it has to be. So grab 2nd gen Legacy axles, they bolt in to a WRX-compatible diff, and work with your hubs.

Ok, lol .. Thanks man.

I have a snow rally race at the end of month, just want to be certain I have everything needed to convert to the CUSCO LSD before I commence the work.
At some point I have already gathered all this info but I'm suffering from memory loss.