Hey William,

That's what did it. I am 100% sure now. Look at this information:

92-00 SC300
6 cyl, AT (4.27 ratio)

92-96 MKIV Supra:
w/o turbo; (4.27 ratio)
w/turbo, AT (3.769 ratio) Limited Slip

97-98 MKIV Supra:
w/o turbo; (4.08 ratio)
w/turbo, AT (3.769 ratio)

Taken from:

https://www.clublexus.com/forums/sho...ght=diff+ratio

I think you should be fine as long as you don't make any high speed runs. Guess I did a few too many. I'm looking for a used automatic Supra TT diff now. I hope I find one with LSD.

Chris

 

Chris,

Did you have the sub-throttle TPS working or did you eliminate it with the TRAC block off plates? Also, did your tranny just die all of a sudden or were there any symptoms before it happened(reving really high, having trouble shifting to a different gear, etc.) Good luck finding another used auto tt tranny...

thanks
William

 

I found the transmission pretty easly actually. Sub-throttle TPS? Is that the temp sensor by where the fuild line is coming in or out? If so then SP put a resistor in it so it was not connected. The transmission didn't die right away. I actually heard some strange noise a day before it happened. Then sudnelly it started slipping to what I thought was a major boost leak. Then my tuner said it's a transmission. I have to give it some props. I acctually drove to the tuner like 20 miles with the transmission slipping.

Chris

 

Chris,

The sub throttle TPS sensor is located on the throttle body. If you looked inside your throttle body, there are 2 throttle body plates. The first one is the sub-throttle body plate(also called the TRAC plate) and the second one is the actual throttle body plate. A lot of people on supraforums take out the sub-throttle plate to increase air flow and then take out the sub-throttle TPS and TRAC sensor and cover it with the cover plates.

http://www.mkiv.com/techarticles/tra...fly/index.html

Also, when was the last time you changed your transmission fluid? If you've changed it recently, what was the color of it?

 

It was all new fluid and it was fine. I actually had a Flex-a-lite cooler too. I belive they're disconnected. Why is that important?

Chris

 

Chris,

Read this thread on supraforums.

http://www.supraforums.com/forum/sho...highlight=trac

this might explain why your transmission is dead..

 

Hey William,

Hows your transmission holding up. Looks like I burned mine up with the low ratio diff.

Chris

 

NOt gonna read the links but, HEAT is going to be your number 1 destroyer. Keep your tranny cool atleast one good, fan cooled cooler.. When you remove the traction butterfly it will shift much harder, and faster cause the throttle plate never closer during shifts so its really rough on the tranny. I have Keans Th400 kit and love it BTW. -Brett

 

No doubt. Having a higher ratio rear end will make the transmission run hotter. That's what fried my first tranny.

Chris

 

It will wrap your motor up higher, just like driving around at a higher RPM. That in itself will not do anything to your tranny

 

The tranny will 100% run hotter. The heat coming from the center console was very noticable. When I got the TT rear end it wasn't getting that hot anymore.

Chris

 

Chris,

Sorry to hear that...More money and time down the drain. As for my transmission, I haven't had any problems with it, thank god... Stock differential too....I have one extra tranny cooler and thats it... Do you know if your transmission lines are close to the downpipe? I remember that mine were kinda close so I wrapped them with insulating material. Other than that, I don't know why you are burning up trannys...If you need anything else, just let me know...

William

 

What driveshaft are you using with the the TT auto??

 

do you always have to go TH400 or TH350? Does the adapter plate also fit a 700R4 or 200R4 (gn tranny)???? I like OD


If i had my wish, id do a built 7L60E with stand alone ECU computer, but i dunno if its possible for under 10gs lol

 

SC400 driveshaft along with SC400 transmission output shaft.

Chris