Hello all!

I have a 1996 XJ6 Sovereign that needs a new/rebuild diff. However, a nearby breakers yard has a 1996 XJ6 3.2 Executive that has a working diff.
I know that the diff ratio is probably different, but is it otherwise possible to do a straight swap?

 

I'll answer to my own question after making a few calls to experts, if anyone else is interested.

Yes, a straight swap is possible and shouldn't cause any major problems (hope so).

 

Just make sure the ratio difference is something you can live with.

Your car almost certainly has a 3.58 ratio. I can't swear to this but as far as I know the 3.2s have either a 3.77 or 4.08 ratio. Hopefully someone will chime in to verify.

Going from 3.58 isn't too dramatic but a leap to 4.08 (or whatever it is) might be a bit much. If you do much highway driving you'll probably lose a fair bit of fuel economy due to higher engine rpm. I'm guessing about 400 rpm at 70 mph.

Cheers
DD

 

Yeah, this is pretty much the same info that the expert gave me. My current diff should have a 3.54 ratio and the donor car 4.08 (he'll check it first).

Factory rebuilt diff is something like 2000 euros here, so that's out of the question and even rebuilding the old diff is something that the local shops are reluctant to do...

But it doesn't matter much to me, because most of my driving is short runs in the city area.