Thread: Got a new performance transmission built and installed, same problems occuring.

Well prior to getting this transmission built and installed, i've had 2 other stock transmissions. My first one died with the P0742 TCC stuck on. My second stock one was a N/A trans with an hd differential slapped on it. It was fine and dandy for a while, then something strange started to happen. After my car got retuned for a 3.2 setup i started noticing some wierd shifting. When the car would go from first to second, second to third, third to fourth, basically any time it shifted up into a gear, it felt like it had no power for 3-4 seconds, then it would go. It felt like something was caught, it would sit at whatever rpms it shifted to the next gear then would sit on it for 3-4 seconds, then climb the gear. After this had started my transmission decided to completely toast, I lost 1st, 4th, and then at the end of its life it did the P0742 TCC stuck on.

My thoughts were a new transmission. So a friend of the family who has been building automatics since 1987 built me a transmission. He has owned several 3800 powered Fiero's and also a handful of GTP's and built the transmissions for them and has a pretty good rep for what he does. He pulled my trans, and to ensure that he wouldn't second guess himself, he used a different transmission core to work with. He completely overhauled it pretty much to triple edge spec, and put it in for me also. We both go out to drive it and what do you know, it's doing the same EXACT thing the last transmission did. Every upshift took 3-4 seconds for it to feel like it would have any power. And later that night after me picking it up i got the same infamous code P0742 TCC stuck on and it did it's usual of bucking and stalling out. Him and I figured it had to be PCM related in the tune because that's when all this started was when I got my 3.2 tune. So I went home, put in the stock computer and pulley. It STILL is doing the exact same thing, every upshift takes 3-4 seconds to feel like it is going to go anywhere, and on the way home from taking the car out to drive it ( i haven't beat on it at all) i get the same FREAKING code and problem of bucking and stalling P0742 TCC stuck on.

I'm so lost and puzzled. He's willing to do anything to help me with it and told me it would be fixed right but right now we are perplexed on the issue. Could it be wiring? Is it engine related? I just need some input because I'm so frustrated i could honestly punch a wall. I just don't want an issue other than the trans like wiring to grenade this new beefed trans.

Are you still using that stock Torque Converter? If so, I'll kick you.

It's a stock stall speed, but it is a new torque converter. I'm lost man...

Because I was pretty sure he was using the stock one that was eating up his transmissions before hand like we had thought...but since he has a new one...nevamindz. BTW BRIAN...check yo fone

i think i might kn ow wht is wrong most the time the p0742 code i caused by either failed tcc or particles from the torqconverter getting stuck in the solinoid i would flush ur radiator because chances are when u put the new trans in u ran the old crap throught the new trans and got chunkies in there

Originally Posted by nascartech

i think i might kn ow wht is wrong most the time the p0742 code i caused by either failed tcc or particles from the torqconverter getting stuck in the solinoid i would flush ur radiator because chances are when u put the new trans in u ran the old crap throught the new trans and got chunkies in there

This is a good point. If the lines and radiator cooler weren't completely flushed, it could still be circulating the old TC particles that were in there all along. Of course, I assume he installed a new TCC solenoid on the rebuild and didn't just transfer the old one?

Nothing from the old transmission carried over. He said he flushed the trans cooler in the radiator, I asked him. Maybe it is clogged, idk, but on friday he's going to use a scan tool while i'm driving to look at things. I judt don't get why i have such a lack of power of shifts, then like a light switch the power is magically there after a few seconds. And it doesn't matter whether boosting or not, or wot or part throttle, every upshift does it.

Something hanging up or sticking in valve body? Or did he rebuild that too?

Rebuilt valve body, he said once we eliminate all other possibilities hed crack it open and check the valve body and install another tcc solenoid and apply valve. He can do it in about 2-3 hours, but he is pretty much certain it's not the transmission since it's the same exact problem. On friday I have the day off and me and him are going to do some checking on it. He has a scanner and is going to monitor it while i'm driving, and go from there.

Here is a video, the quality is crappy because its from my phone, but listen for the change in exhaust tone at 11 seconds. It feels like the car gets kicked in the rearend and it actually moves, really fast. In the video it reminds of VVT or VTEC the way it changes tone then goes. Just watch and listen, it shifts into second at 8 seconds, then decides to actually rap the gear out and go at 11 seconds. I am at part throttle feathering in first to not blow the tires off, then i'm at WOT at the end of first and the rest of the way.

thats weird how its bogs then kicks in

Bump for more input. Brian (Reptile) messed with the tuning a bit and managed to change some things for the better, thanks Brian, but the problem is still a bit there. 1-2 at WOT will sometimes not do it now, but 2-3 is a whole nother story. 2-3 at WOT shifts at around 6k then sits at about 3750 in 3rd for like 6 seconds, ridiculously long, then gets a match lit under its balls and runs like a bat outta hell. I just cant wrap my head around why it's every single gear....

Anyone else?

Did you end up checking the wiring yet? When I installed my turbo, there was so much **** over the top of the trans that I couldn't see my harness was touching the downpipe. Burnt through it, trans went in limp mode, I repaired the harness and was back in business. Even if you don't get a voltage code or anything, I would still check it out if your having TCC issues.

I would make a list of everything that has been changed or when it started doing it. Rule out everything.