4L80E Transbrake Info

Looks like they are having a few difficulties, if only they knew how easy it could be but then it wouldn't be "complex" enough I guess. I'm actually quite surprised that someone hasn't got one going yet considering it's possibilities for extreme HP applications.

They are using the accumulator valve as the brake valve, it crosses into the torque signal circuit, actuator feed, and has reverse oil plumbed to it.

I think I have an idea what the issue is but I don't have a VB here to confirm.

I have everything working except reverse, and in reverse my pressure will sit at 75 psi, then spike to 250 psi, and then blow off. The result is a car that slams into and out of reverse.

I've built DOZENS of 4L80Es successfully for performance use, probably well over 1000 TH350s, Th400s, 200-4Rs, Glides, C4s, C6s, 727s, and even got to play with an A4LD the other day :rolleyes:

I think the torque signal circuit and the way it is used by the solenoid is the issue but I'm not going to "R&D" the junk for him.

It has a design flaw period and he's passing it off as good.
I hope so...
Yours is going on this trans in 2 weeks. :biggrin:

I'm a bit agitated over being lied to by this guy. "Oh Yeah, we have lots of them out there working fine, yet I can't confirm ANYBODY that has one installed and working. I can't make it work, another pro builder can't, and one LS1Tech member having the same issues. HMM...

I guess you could consider it successful. The brake DOES work, but reverse slams into and out of gear, and apparently the auto version locks up in forward gears, has no reverse, and will lock up when in manual low when the PCM commands 2nd.

Not to mention the parts being mismachined by some idiot who can't read a caliper or drawing.
Will be releasing Aluminum Billet manual reverse VB with trans brake. Built from clean sheet of paper. There will also be a spragless version to follow:wink:
TCI's reverse manual transbrake valve for the 4L80E works flawlessly. TCC lockup is available in 4th gear.

This valve body utilizes the overrun clutch in 1,2,and 3rd gears. This feature takes the load off the input roller clutch assembly.

There are two part numbers; 274500(91-96) & 274501(97-up).
Chris, I didn'y say the 80E brake was the only one on the market. Why isn't yours on your web site or did I overlook it?

Does yours utilize the overrun clutches in all gears except overdrive?

I work for TCI and I designed the valve body along with the six speed valve body. Just letting everyone on this board know.
Some of our items havent been uploaded to the site.It is on the trans page.Anyhow just leaving the overrun clutches on in 1/2 and 3 is not all you have to do.you have to leave the rear band on in 1st,the int band on in 2nd as well.If you didnt do this it will never be right.Im not really concerned with how it works .I do things here my way.Good luck at TCI.
Geez.......... of course you can do things your way in your business. I'm just stating the fact, " if the overrun frictions aren't applied at launch, the input(overdrive roller clutch) is taking the shock load of coupling the input shaft to the forward clutch assembly.

I meant no disrespect to you or your company. As a matter of fact we're impressed with your new gearset for the 700/4L60E transmissions.

Have a great day.
What year 4L80E is the most desired? And once you have a stock 4L80E whats needed make it with stand some serious power without breaking the bank? Chris, you ready to sponsor my Buick?????????? I am a great advertising platform for ya.............
Im still waiting for that test transmission we've been supposed to be getting for the last 2 years :rolleyes: :rolleyes: