I just had a local shop rebuild my th-350 and install a transbrake. 1st, 2nd, and 3rd gears work just fine but reverse does nothing. I don't have the wiring hooked up to the transbrake so that can't be the issue. The shifter lingage is adjusted perfect, I triple checked that. Anyone know what could cause this?

I'm hoping its an easy fix so I won't have to pull the trans again. Of course now its the holiday weekend and I won't be able to call the shop until tuesday.

 

There are transbrakes that need to have the transbrake activated to use reverse. The one in my powerglide is like that. Transbrakes activate the reverse circuit when in first gear to lock the tranny. The way the valve body is designed, it will have no effect when in any other forward gear.

Typically the transbrake reverse circuit is activated to back up. You can shift to neutral and push the transbrake button to back up without having to go through the reverse lockout to put the shifter into reverse.

Some racers use the transbrake this way with the switch mounted on the steering wheel. Although it works fine when you're backing up in a straight line, it's difficult to hold the button down when backing out of a pit stall and need to turn. I simply wired my transbrake wiring through the reverse switch in my shifter so when I put the shifter into reverse, the transbrake activates allowing me to back up.

My delay box also has an override feature that allows me to push another button to activate the transbrake to back up without going through the delay box timers but I don't use that feature.

Wire up the transbrake and try again.

 

Thanks for the info, I'll give that a try.

 

sorry not trying to hijack but since yall where on the subject i was wondering if any made or if it was even possible to find a transbrake for a th400 that still had auto shifting capabilities

 

I am sure if you apply 12 volts to the wire your reverse will work. Most trans brakes these days use 12 for reverse.

89importeater I have never seen a trans brake that will allow for auto shifting. In my opinion, there might be one out there but I do not think so.

 

You guys were right, once I wired up the solenoid it worked. I read the directions but missed that once sentence that mentioned that Thanks for the help.

 

You should be able to back up in reverse and neutral when the transbrake button is pressed.

I don't think there's any transbrake valve body that allows full auto shifting when left in drive. You can get manual valve bodies that still operate like a normal valve body when left in D.