It's not the LSD that dictates the gear ratio. You can install a LSD in your stock pumpking and still retain your gear ratio. For example, I have TRD in my SC300 pumpking and still have the same gear ratio of 4.27. YOu have to change the ring gear to change the ratio. LSD is just away of getting the power to the wheels. Some correct me if I am wrong., below are the gear ratio for some lexus and toyota cars. Thank you search function. If you swap out the whole rearend (pumpkin) of your car with a supra or SC400, with LSD installed then you will have a different gear ratio. But just dropping the LSD in the stock pumpkin. No change, just more grip.
From Lextreme's forum
1993-1998 Supra TT manual - 3.133 (torsen)
1998+ Lexus V8 Cars VVTi - 3.266 (open differential only)
1990-1997 LS400 - 3.62 (open differential only)
1993-1996 Supra TT auto - 3.769 (torsen, 3.77 not the usual 3.76 quoted)
1997-1998 Supra TT auto - 3.769 (open standard, torsen available)
1992-1997 Lexus SC400 - 3.912 (open differential only)
1992-1998 Lexus SC300 manual - 4.08 (open differential only)
1997-1998 Supra non turbo - 4.08 (open standard, limited slip available)
1992-2000 Lexus SC300 automatic - 4.272 (open differential only)
1993-1996 Supra non turbo - 4.272 (open standard, limited slip available)
nate579 - hello.
I know from the words of other car owners that FGR = 47:11 = 4.273 mm. reducer SC 300-97; Toyota Soarer JZZ31/30 has the size - 8.5 "(8.5" = 215.90 mm.), But I do not correct this. I have not found information about it.
What do you say?
Thank you for your attention.
Struggling to find a LSD for my SC300 (95)... will the earlier supra ones fit? I see one of those junky OBX Quaife knockoffs listed for the MKIII supra - that'd do for my application if it fits the SC... anybody know?
so now I'm in the hunt for an Auto TT LSD after reading the thread. I would prefer getting the LSD itself and then installing it into my stock pumpkin. However, it looks like labor alone is around $350 from a local trans shop around me. Has anyone tried installing it themselves?
Alternatively, I guess I can find the entire pumpkin, it would almost be plug and play, but the speedo won't match because of the gearing...
hahah.... man this is old.
Oddly enough now i work at superior axle and gear and sell differential parts all day long LOL!!
Setting up gears in not the hardest thing in the world however it is crucial. you will need a backlash measuring tool and an inch pound torque wrench. it could be done right someones first time with the proper guidance.
A lot of people would argue this with me but seriously all it is is PATIENTS. follow instructions, be patient, check your work and don't settle for an "OK" looking gear pattern.
If you do bring it to a shop make sure they have experience in gear set ups.
I have a good gear install write-up but the PDF is too large to attach.
I will Zip the file when i get home and post it here.
I got er done. Easy peasy. Did a build up with pics on Lextreme.
99 SC300 auto diff to get the 4.27 gears, Brand new OEM Supra Torsen diff. Bought new ring gear bolts. Heated the gear on a hot plate for install. Worked fine. Didn't change side or pinion bearings. Swapped the rear diff cover from my 91 diff (bolt patter is different where it mounts to the body). Fabricated new front mounts (different than the 91 LS which only has one front mount). Tig welded the new mounts to the LS body, mounted up the diff, and away we go. Got 2 (14hr) races on it. works great.
Looks like everyone is only selling the entire Auto TT pumpkin.... I guess I would have to deal with the longer gearing... which is fine. What do I need to fit it into my car to be a drop in? I've read I need the companion flange and that's it. Do I need new axles too?
Okay, the original question is the same one I have. How much did it cost to install a trd LSD in a loose sc300 pumpkin? I just droped mine of at a local shop and they told me they eould key me know the price soon. (scarry) I was thinking $200, what do y'all think?