I am on my 3rd Turbo 400? Can anyone tell me a good transmission for 650 ft/lb of torque? I am eating the 400's like candy? The place that built it the last time told me that I could not break it, boy was he wrong. He will cover it, I am just tired of swapping it out! Any suggestions on trans choices?:confused:

I'm using a TH400, but it took a reverse manual valve body to make it shift in a timely manner. I went thru the same thing when I first swapped to a th400 from a th350.

I have been using/abusing my th400 for the last 8 years with no problems. It is a reverse manual valve body from ATI. Last time at the chassis dyno it was 721hp and 784 tq with a 150 shot of squeeze. Good luck

I am on my 3rd Turbo 400? Can anyone tell me a good transmission for 650 ft/lb of torque? I am eating the 400's like candy? The place that built it the last time told me that I could not break it, boy was he wrong. He will cover it, I am just tired of swapping it out! Any suggestions on trans choices?:confused:

Where are you located ?

What's failing?

Intermediate sprag or direct clutches?

What's failing?

Intermediate sprag or direct clutches?

Don't know on the last build? It is leaking from the front??

Where are you located ?

South Chicago Suburbs or Channahon, IL

Before you can determine how to resolve the issues, you need to know what's failing each time.

Th400's even mildly upgraded are tough transmissions. I wonder if something in your driving style is abusing the trans and contributing to the issues your having.

Is this in a drag car, street car, or what?

If drag, how are you doing your burnout?

BTW, I don't consider a leak a failure, just a leak. Could be the converter hub seal, or the pump O-ring, etc.

Surely need more info to know what's going on each time you say it failed.

Before you can determine how to resolve the issues, you need to know what's failing each time.

Th400's even mildly upgraded are tough transmissions. I wonder if something in your driving style is abusing the trans and contributing to the issues your having.

Is this in a drag car, street car, or what? No.

If drag, how are you doing your burnout? Just nail it from a rolling start.

BTW, I don't consider a leak a failure, just a leak. Could be the converter hub seal, or the pump O-ring, etc.

Surely need more info to know what's going on each time you say it failed.


It is a street car with street tires. No race track, the only burn outs I do are when I am rolling and nail it. It is leaking in the front, I have no first gear, It surges something terrible in drive, oh yeah when it shifts, it sounds like someone has a power steering car against a curb and is trying to turn the wheel. It squeels like crazy when it shifts. It also goes between gears when driving? The fluid is burnt very badly and stinks.

And to answer many questions, No I did not do a neutral drop! No brake torques or anything just plain old failure again.

I don't know what keeps happening to the trans, if my driving style is bad then I need an army tank. All I do is go out on the weekends and cruse, I don't beat on it until it is at operating temp and then it is questionable if I am actually beating on it. So I will lay a 300' black mark on a deserted road every once and awhile! That is what I built it for. If it can't spin street tires, then what am I going to do with ET Streets?

I am going to stay with the trans when it gets broken down to see what is exactly wrong and will post it later, first I have to get it home and then get it out of the car. And then it will be a beer coaster for the rest of the year. New baby due end of July!!

Before you can determine how to resolve the issues, you need to know what's failing each time.

Th400's even mildly upgraded are tough transmissions. I wonder if something in your driving style is abusing the trans and contributing to the issues your having.

Is this in a drag car, street car, or what?

If drag, how are you doing your burnout?

BTW, I don't consider a leak a failure, just a leak. Could be the converter hub seal, or the pump O-ring, etc.

Surely need more info to know what's going on each time you say it failed.


You covered all I was going to ask.

Never do a burn out in 1st, th400s are tough, wonder if it is an error in the reassembly process?

why can't you do a burnout in first?

why can't you do a burnout in first?

first gear doesn't create enough wheel speed to do any good. Shifting from first to second while doing a burnout can shock the sprag and break it.

Broke two locally built TH400's.
Coan built manual-reverse TH400 has been in the car for two years now...sees occasional abuse. ;)
Functions just fine. :thumbsup:

i purchased a t 400 from chris at www.ckperformance.com he will give you A price break cause your a tc member im pushing 688 tq and havent hurt it yet . its a stage 2 good for 1200 plus hp and tq with a mechanical modualtor its a awsome trans.

first gear doesn't create enough wheel speed to do any good. Shifting from first to second while doing a burnout can shock the sprag and break it.


I thought that you wanted to shift to second asap when doing your burnout and then just roll out of the burnout in second or high gear.

I thought that you wanted to shift to second asap when doing your burnout and then just roll out of the burnout in second or high gear.

I have always started in second gear, immediately shift to high, then power out.

It's a waste to start in first. A car with any power should be able to start in second gear.

I have a similar setup in my 70. I blew the first TH400 to pieces. The one in there now has been in there for 5 years now and I can say that I do beat the snot out of it. Mine has to be manually upshifted. The guy that built it for me said it was necessary so the pressures were correct when it was time for shifting. He said if I let it go by itself, it will shift too soon and the pressures will be too low and cause it to slip and burn up the clutches. He also told me not to roll out of a burnout in high gear with it, start in first, hit second at 5000 RPM's then roll out. I've done everything he told me to do and it's held up great so far and it has over 10,000 very hard miles on it. It does leak, however, after it sits idle for about 4 days or so.

I thought that you wanted to shift to second asap when doing your burnout and then just roll out of the burnout in second or high gear. If the tires are blazing and they STOP turning quickly you can kiss the intermediate sprag goodby, even on street tires. If you are not "under power" when it chirps it will probably live.