Picked up my car from MTI a couple of days ago after installing heads, cam, and yank ss3200. Drove it home about 180 miles at around 70 mph on I-10. Drove it the next day when the SES light came on and it felt like the tranny was slipping while climbing a small hill in 3rd. MTI arranged for a vehicle transport and it was sent back to MTI yesterday. Today I find out that the 3 and 4 gear clutches and bands are burnt up. The car drove fine to MTI prior to the install and it only has 13,000 miles on it. I was told to baby it after the swap for about 500 miles, which I was doing.

My question is..how in the hell do these clutches get burned up? Something just doesn't seem right. Now my car is at MTI and my transmission is at Century. They told me they could fix the problem but it was just a bandaid. Looks like I am forced to buy the stage one kit for around $2400, this after dropping nearly $7G at MTI. I'm not a happy camper. I thought it might have been the converter, but MTI said the converter was fine... by the way, this car is my wifes and she babies the **** out of it. Sorry so long, any ideas???

 

I have a similiar story.
I built a V-8 S-10 from the ground up. It started out mild, it had a 700R4 that I built to stock specs.
Then I added heads and cam, a major power difference and it would slip during the 2-3 shift.
This would have burned up the 3-4 clutch in no time.
Someone online told me the stock clearances for the 3-4 clutch are no good for performance use. Mine was set at .090. Well within stock specs and it's the same on a 4L60E.
I did nothing but pull the trans and reduce the 3-4 clearance from .090 to .038.
Problem solved.
Never slipped a bit with the weak engine.
Now you do have a VCM contolled trans so that may be a seperate issue.

 

what gears do you have in the back?


if you babied it and never really got up above 3200+ RPMS, then your converter would have never truly locked up and your tranny would in an essence be slipping the entire drive home of I think you said 180 miles. Just a thought

and I did not see that you had a cooler on the tranny.... need one of those as well

coker

 

I have the standard 3:23.1 gearing. I cruised home at 70 and the converter was locked. When the ses light came on, it wouldn't lock up anymore. I have a big tranny cooler also. This whole situation just baffles me...I read about guys here abusing their stock tranny at the track and don't have any problems. I have the same tranny in my truck with over 100,000 hard miles and not a problem.

 

I noticed in your post no mention of any tests....also didn't see where you mention what code set the ses light....I'd be asking somemore questions...like whats the line rise??? Heads and cams don't cause 3/4 to burn up.....Hope this helps Dave

 

Without knowing the SES code, the most obvious suggestion is that the tranny was underfilled with fluid, got hot, and those clutches got fried as you went down the freeway.

 

If they neglected to check fluids after all the work was done the previous poster could have an excellent point. I'd be asking a few questions. Good luck man.

 

If I remember right the code was P0756 which has something to do with 2 to 3 shifts. After getting it home from Houston and before shutting the car off, I checked the tranny fluid and it was about half a quart over-filled. What surprised me was the tranny fluid didn't seem that hot. I'm pretty sure it didn't overheat. Century told me overfilling will not cause this damage. MTI tuned the car and told me they didn't mess with the line pressure. I just don't understand how this happened.

 

with the 3-4 clucth pack if the clearance isn't just right it slips them. slipping makes heat that burns them out( slick no grip) I just had my trans rebuilt (last week) they didn't get the clearance right on the 3-4 servo 261 miles later no 3-4 gears. I'm pissed off with you,dam 3-4s I'm ordering a EVL trans

 

You sure?
Yes the trans doesn't say , oh different heads and cam time to burn up.
It's the added power.
If your trans is barely holding on and you go and add 100+ hp then you're going to find it's weak spot. And from what I've seen the 3-4 clutch is a weak spot even in stock form with stock engines. Even if it lasts for 300,000 miles chances are real good the 3-4's will be what went first.

 

Yeah, but as he said, the car has 13,000 on it, It's his wife's car who babies it when she drives, he was babying it for the first 500 miles as instructed, and he was cruising at 70mph locked up. My guess is that he didn't even floor it ... if that's the case, the only thing I can think of is that the 3-4 clearances weren't right from the factory - coincidence that they burned up when they did. But somehow, that's just hard to believe, isn't it?

 

I've never seen a car with heads and cam blow through a set of 3/4 clutchs, I've never seen this....what I have seen however is a mal adjusted tps after a head and cam install. I'm not saying that is what has happened....we are all guessing...there are no stated facts other than 3/4 clutchs and band are burned up,(why? what caused this to burn? how did this happen?) the trans was overfull(was it venting? subpose this would cause the 3/4 to burn? it could with several qts over full,but we'd have venting), and there was a code 756,(we're not even sure what code it is) he thinks.
I agree with century that over filling wouldn't be that big of a deal......It's real easy to say your 3/4 clutchs are burned, and I'm sure your flattered to think that something you built(or Had built) is sooooooooo powerfull that it blew through your 3/4 clutchs. But thats where it stops.
These Transmissions have 8 to 11 external (to the transmission)electrical controllers that controll the transmission, Line rise and shifting....All of them MUST be working flawlessly, and together for proper line rise to be achieved.(how many of these controllers are disturbed when you have heads and cams installed)? How many post start out just like this one??? How many have you said my stock transmission lasted 100,000 miles,,and my built transmission only lasted me 2000 miles???? You take the old tranny out and install the new one right back into the same ole shitty controll system and expect it to work......It's not these transmissions folks it's the controllers. Simply put.....they suck .....at best.
Clutchs just don't burn because new heads were installed. Clutchs burn like crazy because of low line rise.... fix that and you'll fix these transmission problems...... Jus my two cents...It is not intended to slamb anyone....... I hope this helps Dave

 

is there anything that we can do without the tuning software to raise the line rise? dave if the car is tuned for say 4.11's and i'm running the 3.23's could this also cause shifting issues?

 

Yes there are several things that can be done to raise your line pressure. One is to install a good quality shift kit.......... the other would be install a transgo vac. modulator. In my opinon this is the one of the most important things you can do to these trannys(vacume modulator), get that stock system out of the line rise business. As far as your programing goes I think it would create shifting problems.....you'd be better off with a tuner answering that question.....kinda outa my realm. I hope this helps Dave