Tough TH400 Reverse pattern manual shift died - Any thoughs

Hey guys any thoughts on this. Had a professional built th400 reverse pattern trans with 2200 stall put in the car all new work done on it. Good to 1000 hp. The builder warranties his work. It has Absoultly amazing shifts - really snappy and no issues at all. We installed an electric fan cooler as well and went to the track, it performed well and I put around 1500 miles on it in town and on the highway. The other day I'm coming down a slope and do a 2nd to 3 rd change at half throttle (Honestly) and the car powers out and revs right up so I pull over. I find I've got No gears - not even reverse. So I call a tow truck and get it home, I jacked it up and find no leaks on the trans and no burnt oil and the differential is fine and free. This ones got me stumped - Anyone had this happen to them?

 

Kind of sounds like what happend to the TH400 in the Lark at the track Saturday. I suspect the pump went out.

 

You will find out what broke, when the trans is taken
apart (assumes fluid & filter OK). There is a very slim
chance, that a valve body swap could fix it.
good luck, Bruce Roe

 

Thanks guys,
It's coming out today. Hopefully v/Body or pump will be the problem I'll update when it's fixed.

 

My transmission repair guy is a truck puller racer (WI).
He changed my turbo 400 from thrust washers to a torrington thrust bearing. Said it reduces fluid temp and boosts horsepower more than you would think.
He also installed a Allison transmission metal filter, instead of the paper filter.
Also put in a street shift kit.
Seems to be working good at this point.
Will know more when the 350 engine comes out and the Jim W. 470 goes in.
Bruce in Kandahar

 

Turns out it's the pump. I thought this trans was built tuff? Mabe I'm too hard on my gear! Anyone know of any good pump upgrades? or if there are any ways to trick them up?

 

What actually failed in the pump? I can't think of why a pump would fail due to high engine output or rpm. The converter hub simply spins the pump gear and pressure is limited by the relief spring. Maybe the spring is shimmed for too much pressure, or there's some odd interference between the converter's hub at the pump gear interface? Some photos of the pump tear-down might help.

Devon

 

I'm Not sure - It's going back to the trans builder with the new converter. So I should find out shortly. The funny thing is the last transmission with the old converter had a pump failure as well. There was steel all through that trans and converter. It actually siezed up and I had to disconnect the drive shaft to get it to move. Could it have anything to do with the fly wheel mounting?

 

The new news today from the transmission builder is that the torque converter exploded inside. Transmission is ok, he checked her out, I asked again what the trans is good for and he assured me 88 Ft/Lbs at the wheels - No problem. Now we have to chase the Torque converter company, they are called Taipan and the damn thing cost me $750 and was sposed to be good for a 100 shot of Nitrous, they already supplied a the wrong converter to me 2 month ago and I wore the labor there. This time they are going to wear it. How hard can it be to build a race converter when that is your bussiness?

 

88 ft/lbs at the wheels whoops.

 

A few post ago you said with some certainty the pump failed. Now your guy is saying the converter failed. Which is it and how do you know?

 

Sorry. To clarify it went on a tow truck from my houdr to the Mechanics shop. He started it and said the whining/gear sound is the pump gone, (Or not working) That was his opinion at the time. He was under instructions by the transmission builder not to dismantle anything, just to pull it out and send it 20 klms down the road to him because it comes with a warranty. Today I get a call from the mechanic to call the Trans builder so I did and the trans builder said it's the torque conveter

Blade deformation and fragmentation: If subjected to abrupt loading or excessive heating of the converter, pump and/or turbine blades may be deformed, separated from their hubs and/or annular rings, or may break up into fragments. At the least, such a failure will result in a significant loss of efficiency, producing symptoms similar (although less pronounced) to those accompanying stator clutch failure. In extreme cases, catastrophic destruction of the converter will occur.

So now it's over to the torque converter builder to warranty his work.
I guess i jumped the gun when the mechanic gave his opinion just by listening to it, shouldn't have updated so quickly.

 

You meant 880 Ft-Lbs, right? I can pull more torque than 88 Ft-Lbs with one arm. I hope it gets taken care of properly by the vendors.

 

Thats correct 800 ft/Lbs at the wheels.
Southside Dyno are the mechanics who do the work on my car. They are going to pursue Taipan the torque converter builders for the labor and what not to get the box in/out and transported/stripped down at the trans builders shop. If they don't play the game we'll take them to small claims court and tell everyone we know in the racing community their work has gone done hill badly.

 

Now you have me wondering if I should bite the bullit and buy a new converter to go in with the new trans Im having built or take a chance on putting the old one in. Becouse I have to rent a trans jack to do the work I wanted to do it all in one shot. Last time it was pulled and put back in it only took a few hours.

 

you MUST flush all the lines and cooler before re-installing the new trans/converter otherwise you risk contaminating the new with crap that is in the lines or cooler. :Smarty:

 

I'd get a new converter if you have a good deal of money in your transmission or mabe get a professional flush done on it if she's a good one