legacycentral bbs

So about 7k ago i chipped a tooth on my rear diff. The whining is driving me nuts, so i figured id finally see about fixing it this weekend. Being a cheapass, i was just going to pull a diff off a P&P car and slap it in. Since it's going to be a used unit, i figure that a AT will be kinder to a rear diff since it won't have to put up with the torque loading and unloading like a manual does. This is a good assumption, right? Anyway, what years had a 4.11 on the automatics? My 90 fsm says that the 90's do, when was the change to 3.9?

My '91 has a 4.11 I believe.

90-91 only. I think the whole torque deal has to do with the driveshaft. If the center joint is a DOJ it doesn't transmit as much torque, if the center joint is a U-joint it transmits more torque.

hey if you've got 4.11's you could probably swap a locking rear diff from an audi.. I've been doing tons of research to try and do this with a 3.9 transmission in my xt6...

my "research" can be found at http://eagle.bsd.st/~dertow/links/audidifflock.txt

and

http://www.ultimatesubaru.net/forum/sho ... 775&page=3

as well as
http://www.xt6.net/forum/viewtopic.php?t=4751

Why would you want to lock the rear differential in a street car?

we got lots of snow and ice here... guess you don't in CA though