FEAR LS

iTrader: (8)

I have a Stage II RMVB w/Transbrake TH400 built by Jake's Performance. It was perfect until I rolled a sprag... That was my fault. I replaced the sprag and got it all back together.

Now my issue is: When the trans fluid gets to operating temp, the reverse doesn't want to hold on the brake and when just trying to reverse normally it slips. All the forward gears including third work great! I really need to get this brake working again because I'm going turbo and I need this brake!!!

The transmission is out of the car. So I can't put a pressure gauge on it, and honestly I don't even know what the hell that does. I know I have a problem with reverse, so how will seeing it has low pressure help? lol

Bare with me as I am by no means a transmission expert. I don't have too many diagrams to go off of either.

I have an aluminum separator plate and the one and only check ball is installed above the spring.

What should I check for?

Jake's Performance

iTrader: (2)

Reverse takes more pressure than forward typically. So a pressure check can show problems.

Did you look at the direct clutches? Were they OK?

Might have cut a seal on that drum.

FEAR LS

iTrader: (8)

Reverse not working shows me there's a problem? I don't need to see low pressure to realize it doesn't work. If the pressures isolated a component I could see a pressure check useful. But that is neither here nor there as the transmission is out of the car. I really appreciate your response by the way. I was wanting you to chime in. You sent this thing in perfect working condition just so the record is set straight. lol I just rolled that sprag and replaced it myself. (That's the issue haha)

The direct clutches were in good shape, a few heat marks but other than that in working condition.

I replaced the drum since the sprag chewed it up. I did replace the seals since I replaced the drum.

Why would it work fine cold, but hot it doesn't?

Jake's Performance

iTrader: (2)

A pressure check will help isolate.
If you have a big leak on a circuit, the pressure will drop when you use that circuit.

You can isolate the issue in the car, so you have a good idea where to look, possibly in the VB, or possibly internal.

FEAR LS

iTrader: (8)

Gotcha... So being that it's out of the car. Where would you recommend I look as is? Any technical data I could source from somewhere to help with the issue?

Servo? Reverse band?

FEAR LS

iTrader: (8)

Any info on how long the reverse servo apply piston pin should be?

If I have the transmission in gear and the reverse servo pushed down to it's max, should it stop the output shaft?

Jake's Performance

iTrader: (2)

http://www.jakesperformance.com/400_...djustment.html