TH 400 overheating
TH 400 overheating I swapped over from a M6 to a TH400 recently and when I did I used all new parts for the swap (as far as cooler, lines, TC, etc.) The only thing that wasn't new was the transmission. It was supposed to be a freshly rebuilt unit, it has a RMVB, and a T-brake. It is set up for a non-locking converter, and has no engine braking. I installed a tranny temperature guage with the sender tapped into the fluid "out" line right off of the tranny. I took the car out the other day in mid 40 degree weather and within a mile and a half the trans temp was up to 250 degrees. 
I run the B&M 70274 - SuperCooler rated at 29,200 BTU 11"x11"x1-1/2" The car has a Vigilante 3600 stall.
Does anyone have any idea what might be causing the tranny to get so hot? I know this isn't the most street friendly application, but I would still like to at least be able to drive it a decent way from home.
All suggestions are appreciated.
-Jason
I run the B&M 70274 - SuperCooler rated at 29,200 BTU 11"x11"x1-1/2" The car has a Vigilante 3600 stall.Does anyone have any idea what might be causing the tranny to get so hot? I know this isn't the most street friendly application, but I would still like to at least be able to drive it a decent way from home.
All suggestions are appreciated.
-Jason
well with that much heat in that short a time , and no slipping etc noticable. I would say look at the converter,
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Its possible unless you have a blocked or restricted cooler. I can imagine anything else that could generate that much heat that fast
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the line to cooler is the converter out temp and that reading can go over 320 deg. when worked hard!
check the temp at a cruise in 2th gear around 4000 and see what the temp is!
The converter you have is around 4000 stall and is working (slipping) in the lower rpm range so it will make some heat.
for a transmission oil temp it is better to go to the pan for a reading
we use a temp sensor on both cooler lines this will help tell you what is going on in the converter at the track in high gear
check the temp at a cruise in 2th gear around 4000 and see what the temp is!
The converter you have is around 4000 stall and is working (slipping) in the lower rpm range so it will make some heat.
for a transmission oil temp it is better to go to the pan for a reading
we use a temp sensor on both cooler lines this will help tell you what is going on in the converter at the track in high gear
Thanks to both of you for your help and suggestions. Performabuilt, I hope I don't have any blockage, being that the cooler and the lines are brand new. When I had the lines cut (steel braided) I did blow them out to make sure there wasn't any debris to cause any blockage.
Yank, I will take the car out and try what you said to do. I wanted to put the sensor in the pan for reading the temp, but I tought it would be just as well to put it where I have it now.
Thanks again guys. I'll let you know what I come up with.
Yank, I will take the car out and try what you said to do. I wanted to put the sensor in the pan for reading the temp, but I tought it would be just as well to put it where I have it now.
Thanks again guys. I'll let you know what I come up with.
Smell the fluid and see if it is burnt. I think you may have something wrong with the temp gauge, or you may very well have a kinked line. Its kind of hard to mess up a non-lockup converter. I'm not sure what it is with the people on this board and the trans temp gauges. I swear that the only people in the world that uses them are on here. One of my cars has a Neal Chance bolt together converter, and a glide with pro gears and I drive that on the street all the time. No problems with over heating, ever. I guess if you aren't certain of the quality of the products that you are installing, or putting all out race stuff in a daily driver, then you might need one I guess.
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The fluid doesn't smell burnt. And there is no kink in the cooler lines, or the line to the sender. It's 18 guage wire, and I can see every bit of it going to the sender. The reason I installed a temp guage was that I felt that it was cheap insurance as far as making sure I don't burn up my tranny.
Last edited by blkbird_WS-6; Mar 22, 2007 at 04:24 PM.
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Verdad Gallardo Frustrated!!! Well I ended up buying a new tranny pan and took it down to the local tranny shop and had the sensor for the temp guage plugged into the side of it. Still not doing any better! The only thing is it may have taken a little longer to peg out the guage at 250 degrees, but not much longer. I guess I'll pull it apart, do you guys think I should send the converter back and have it checked out? I don't know what to do, this is all new to me. I've been debating for the last few days about putting the M6 back in, but I'd like to give the auto setup a try at the track. Man I don't know what to do. 
What trany temp guage are you running? Maybe the guage is fruity and isn't working right. I have an autometer ultra-lite hooked up to my th400, and with my hughes full race th400 with rmvb and brake, and with the ultimate 5800 converter I have it has never gone higher then 240, and that was after hot lapping it 3 times at the track with no cool down time at all launching off the transbrake every time too. And I'm only running a flex-a-lite 21x7.5x3/4 cooler, right on the front of the radiator, where the a/c condenser usually is.
I'm gonna guess and say the guage is acting up. I'd try another guage and see what that gets you
I'm gonna guess and say the guage is acting up. I'd try another guage and see what that gets you
I appreciate the response. I have a ultra-lite guage from autometer. It wouldn't be the first time I had guage troubles, my fuel press. guage took a dump 3 weeks after I had it installed, and I had to have it replaced. Is there any way I can check the guage to tell if it's faulty without buying another? If not I'll have to figure out something.
I went to back my car out of the garage to put brakes on my little sisters car and after starting the car and letting it sit for a minute, no more than two, my temp guage was reading where the blue mark is. This was just sitting still!!!
So I backed it out of the garage and it sit for 2 hours. When I went to pull it back in the garage, upon start up it read this...
After two hours of sitting.
It's gotta be the guage!!! I never noticed it doing this before because I had never sat in the car when starting. I've either been dumping tranny fluid in it or something else. It just always threw me off because when I would finally get in to drive it the car would read somewhere between 150 and 180. Then when I would drive down the road it would creep on up to 250 degrees. I'm gonna try to borrow a guage to see if that is definintely the problem. If so, then I will send this one back to Autometer for a replacement.
So I backed it out of the garage and it sit for 2 hours. When I went to pull it back in the garage, upon start up it read this...
After two hours of sitting.
It's gotta be the guage!!! I never noticed it doing this before because I had never sat in the car when starting. I've either been dumping tranny fluid in it or something else. It just always threw me off because when I would finally get in to drive it the car would read somewhere between 150 and 180. Then when I would drive down the road it would creep on up to 250 degrees. I'm gonna try to borrow a guage to see if that is definintely the problem. If so, then I will send this one back to Autometer for a replacement.
sounds like the guage to me. There's no way that by the time the motor's up to temp just sitting in park the tranny would get that hot. Try swapping guages with someone and see what it gets you.
Just to be safe, you do have the tranny full of fluid and whatnot... I mean fill it until a little overflows when you're out driving it so you know it's full, just to be safe. Just trying to make sure there's no other potential problem here.
Just to be safe, you do have the tranny full of fluid and whatnot... I mean fill it until a little overflows when you're out driving it so you know it's full, just to be safe. Just trying to make sure there's no other potential problem here.
