Finally got the house rebuilt since the April 06 fire. Now have time to work on vette. The problem started back in March 06, when I put a e-bay 400 tranny in. Had leaking problem from the start, changed pan, replaced lines ect ect. Finally not leaking overnight any more. This is what is happening now. After running for a few miles transmission dumps transmission fluid out the fill tube. Before you guys tell me it was over filled, belive me it was not. This happens everytime. last time I had to add 1/2 gallon of fluid. This trans hardly got any miles on it at all. Been doing all my own work on these cars for over 20 years. I know all the times I have gone thur this cycle, fill to level when warmed up, drive for awhile, dump fluid, repeat. have a new aluminium radiator with a aux trans cooler. So it`s not even running that hot 200 most of the time. What the ---- is wrong with this piece of garbage. Should I just put a new one in. warrenty from E-bayer long expired, if not for fire stopping my life last year, could have followed a better course of action. really need to resolve. any ideas out there. oh by the way e-bayer was Johnson Preformance.

 

Don't know if this is your problem or not, but there is an o-ring that goes on the end of the fill tube portion that goes into the trany.

 

I'm sorry I can't help you ... but your thread should serve as help & further testament to others ... never buy a motor, trans, diff etc assembly from anywhere you don't know or from where you have little likelyhood of meaningful recourse ... that definately includes ebay. Small/Individual stuff=GO ... assembly=NOGO.

 

A couple ideas.

Pull the trans and take it to a transmission builder. You can try to do it yourself but if you have never done one before I wouldn't suggest learning on your Vette's transmission.

You can also buy a new transmission that's either new or rebuilt with a warranty. That being said, it would be a great opportunity to upgrade to an overdrive transmission like a TH200R4.

 

I would call a few local transmission shops and explain to them the problem you're having. Maybe they've seen this sort of problem before and can recommend a fix.

 

It sounds like there is too much pressure building inside the case.

 

I'm wondering if the cooling lines or cooler are plugged...I know you said they are new, new stuff is sometimes bad.

Steve

 

I know that on TH350s there is a vent tube on the top of the tranny housing. The purpose is to vent excess fluid if it is too high or foams. I would assume that a TH400 should have one of these as well. Sounds like yours is either plugged, bent or just closed off. This won't necesarily keep the fluid in the tranny where it belongs, but it may solve your fill tube problem.

 

That vent tube serves an important purpose. Have you checked it or can you check it?

 

It has a valve in the valve body sticking or a bad o-ring in the valve body. There are a lot of valves in there so it could be a bit of work to locate it. I would pull the valve body out and carefully examine each valve for operation. Shouldn't be all that hard to do. Do yourself a favor and go on ebay and buy a video for overhauling that tranny and get the ASTG book for it. LOTS of good info in there including an extensive troubleshooting guide.

 

What does ASTG stand for?

 

A utomatic
T ransmission
S ervice
G roup

 

Okay, it was backwards. I could have figured that out.