What I'm trying to do is disable the mechanism that allows engine braking when manually shifting the trans. I know that some full manual shift kits make a trans do this, and I know some race trans have this part removed to save weight. I also know that this is how the trans usually works when in full auto mode.

Is there any way to disable this without pulling the trans apart (no problem with fooling around inside the pan, I'm not afraid to experiment a bit with plugging passages in the VB or drilling holes to relieve pressure to a certain seloniod. I'm trying to make the trans road raceable for a few track sessions before I go to a t-56, the goal is to be able to down shift under braking so that i'm in the proper gear coming out of the corner instead of doing the come out of the corner bogged and then down shift routine. For those of you who don't know, down shifting without matching your revs is a recipe for disaster when you are threshold braking.

The trans has some miles on it but it's in good shape. It has a transgo manual auto kit, extra clutches in 3-4 pack, and red clutches througout. It's held up to 40,000 miles of me beating on it with about 300 hp.

 

I believe it is the overrun clutches you want to disable. In OD they are already disabled. By looking at how this is accomplished may be able to figure out which feed to block off.

RBob.

 

That's what I thought, I'll see if I can find some hydraulic schematics for the 700. I got to see an original GM factory service manual for the 700 once, very nice with color coded fluid flow diagrams for every gear and mode. I was supposed to get a copy of some of the pages but the kid never came through and I've lost contact with him over the years.

Rbob, is there anything you don't know???

 

After some searching I've found there is a piston that applies pressure to the overrun clutches, and if the seal on this piston gets mangled then they won't engage......perfect.

The problem is that I haven't found anywhere that shows where this piston is. It looks like I should be able to just yank the piston as the excess pressure is just bled to the forward apply piston.

 

Did you guys have any luck with this over the past 6 years? I am wanting to do the same thing.