I have an 06 Donor & installed an OBX LSD in the transmission which changed the output to male splines.

Doing this means the FFR axles for an 06 will not work. Jim advised getting 04 FFR axles and 04 inner and outer CVs.

He also cautioned me that aftermarket CVs from Cardone had different CV to Axle splines and could not be used.

I bought 04 salvage axle assemblies. I stripped the CVs and found the two rears that I bought had different CV/axle splines. (Who knows if the salvage yard sends you are a “true” Subaru 04) One of them matches the FFR axle and one of them doesn't. So I have to get another rear outer CV.

The problem is….How to tell what splines are in the CV before you buy it and take it apart!!!!

The only externally measurable difference I found is:

Axle Diameter with “good” usable CV is ~0.915
Axle Diameter with “bad” unusable CV is ~0.950

I don’t know if this is always the case, but for those of you with the same issue, maybe this will help.

Any information anyone can add to this thread…please do!

Also anyone with a spare 04 rear lying around please PM me….as you know I need it! Right now I'm 3/4 finished with the axle assemblies

Top Axle alleged Subaru oem 04 incorrect splines ~0.950 diameter axle.
Middle FFR supplied Axle
Bottom 04 (?) with correct splines to match FFR axle ~0.915 diameter.

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