xspsi6

iTrader: (31)

You can use either^^

boost2pt4

I love learning something new.Love this forum

SC400-PHAE

iTrader: (2)

how bad is it driving a welded end? daily driving?

oldManTan

bringing this back from the dead, i was told my car has a TT auto diff but it never locks, or at least i dont think it does, i tried doing some donuts in a wet parking lot and the car just stood still and i think one wheel was just spinning. is a torsen supposed to lock in situation like that? also would a MK3 turbo Clutch type LSD, which is a 1.5 way, work in an SC?

KahnBB6

iTrader: (5)

Well, no USA market (or Canadian) SC's of any generation had LSD options so it definitely would have to have been swapped in. I will say off the bat that this is a very rare thing to encounter with SC's that aren't turbocharged. With an SC400 you'd have stepped down from a 3.916:1 to 3.769:1 ratio (assuming the LSD wasn't custom installed/rebuilt into the casing). Torsen T-1 LSD's as were found in MKIV Supra TT Automatics (and as an ultra rare option on MKIV Supra NA 5-speeds) are considered a 1.5-way LSD. They don't lock in the same way a Detroit Locker does or even a 2-way clutch-type LSD does. Still, even with stock power you should be able to slide around (I can a bit with only 225hp in the dry and very easily in the wet) and you should feel the Torsen shifting your power around. This is especially perceptible on curvy technical roads. There is also the rare tendency given the right conditions for the Torsen T-1 to make the car slide to the left in extreme abnormal loss of traction situations in the wet (one reason high horsepower Supra turbo owners like to switch to TRD 2-way clutch LSDs other than getting aftermarket traction control).

If you're not experiencing the feel of the car straightening out the rear when you induce a tail slide you should have the rear end checked. There is no way to tell if you have a Torsen T-1 for sure unless you can tell by driving the car or by physically pulling the aluminum cover off the differential casing and visually verifying. Up in the air a Torsen T-1 diff acts exactly like an open differential. It also acts exactly like an open differential in the event one wheel becomes unloaded in the air in a racetrack situation (this is an extreme case compared to normal street driven SC's). I read that even rarer (97-98 Turbo only I think and more commonly JDM) Torsen T-2's don't exhibit this behavior. The likelihood of a Torsen T-2 being in that differential from a late model TT Auto is extremely doubtful to improbable.

No, Torsen or clutch-type LSD's from the MKIII Supra / IS300 / IS250 / Cressida / FR-S / BRZ differential family will not work in an SC, GS or MKIV Supra. Some have tried it in a couple of threads but it's not recommended. Unfortunately we don't have it easy for LSD options but the good news is our differential casings and diffs are extremely tough compared to the MKIII style diffs. MKIII clutch-type OEM LSDs also were not very well designed. The rarer Torsen years are better for those cars and even better yet are the aftermarket clutch LSD options for MKIII's like Cusco or OS Giken... which we also have made for our MKIV 200mm style differentials.