[65redone]

I went to the drag strip for the first time today. I have a TH400, with a 4500 rpm stall converter.
First 2 runs went fine,using the foot brake to buid up the revs. I had no traction problems at all, the car went straight off the line. On the third run I decided to use the trans brake. I built up the revs to about 2000 revs using the foot brake first before engaging the trans brake. I then put foot on the gas and the car held on the trans brake,. First problem was- couldn't seem to get many more revs. When I let the button on the trans brake go- the car seemed to bang at the back and all the way up the strip, it felt like the transmission was slipping, resulting in poor performance and a bad run.
Following this, in the pits I pulled the dipstick in the transmission to find the fluid was low- I had previously left it a pint short of the "full mark" but read that this is what you should do when using a trans brake. I topped the fluid up to register on the dipstick.
On the next 2 runs i didn't use the trans brake but the performance was still poor and the transmission felt like it was slipping as though the fluid was still low.
Has anybody got any ideas as to why the transmission is slipping and why the change in performance between the first 2 runs and the latter runs.
I have a 2 step module- the first step is 6000rpm, the second is 7800rpm.

 

[bracketchev1221]

First thing is if you have a 4500 converter, the 1st step of the rev limiter should not be higher than that. Is it possible that the solenoid is stuck still trying to engage reverse in the trans.

 

[65redone]

only had the car 4 months and it came with the 6000 rpm module in place, but it came with a couple of spares including a 3800 rpm module, so will change it to this.As for the solenoid- does it need to be removed to test it and how can it be tested ?

 

[67shovel]

I bought an ex drag 1957 Belair and put it on the street years ago. It had a 4000 stall in a 400 turbo. The guy who sold it told me not to power brake the car with the loose convertor. Said to put it in neutral at the light, rev the motor a couple times to "flash" the torque convertor, pull it into 1st and inch up to the lights. Smack the pedel on the green and the tack ran up to 4000 and off we went. Is that how your suppose to launch a high stall automatic?

 

[bracketchev1221]

If it is an external solenoid, it should be on the passenger side of the trans case. Usually they are held by a little tab and a bolt. You can have someone energize it on and off and see if you feel it clicking. Usually they knock pretty hard. It could be gummed up inside and not allowed to move too freely. There are internal brakes, these require the valve body to be disassembled. Hopefully it is external.

 

[65redone]

The button of the transbrake is connected to the solenoid which is located on the driver's side of the trans case ,so will give it a go at testing this out. Also what is troubling me is why, when the button on the transbrake was pressed, why i couldnt seem to get the revs up to more than what seemed to be 2500 rpm.