What is a transmission brake

Hey everyone, once again pardon my ignorance, but I am still trying to figure out what I have here... The PO mentioned that this CJ5 had a tranny brake, but that it is disconnected. My dad and I have absolutely no clue what that means, what it does, how it works, or how to make it work again. I have pictures posted now at Frappr for anyone that wants to see them. Some of the underside pictures show the large disc shaped drum that is supposedly called the "tranny brake." Can anyone shed some light on the topic? And, If you see anything interesting in one of the photos that I don't have mentioned in my profile, please tell me b/c I probally don't know it is there yet. Thanks again everyone!

http://www.frappr.com/jasonfletcher

 

Do you have an Automatic? Thats the only place I know of a tranny brake. Basicly from my understanding trannybrakes turn the reverse and the 1st gear on at the same time thus locking the tranny. What you are looking at is the parking brake. Which on the dana 18 is on the t-case.

 

What you have is Model 18 tranfer case with a drum emergency brake.
www.hermtheoverdriveguy.com has parts you may need to get it working...


Extreem

 

Parking brakes mounted to a transmission or transfer case instead of the brakes at the axle are sometimes referred to as "transmission brakes" meaning mounted to the transmission instead of the axle. There is another type used on automatic transmissions as mentioned that lock up the transmission as long as a button is held down. It's used for staging in drag racing. Nickmil

 

I'm a newbie here just tearing down my first Jeep (1964 CJ5). My parking brake cable runs through the firewall to a drum brake assembly attached to the back of the transmission. It does not run to the back wheels as I would have expected. If you'd like I can take a pic and send it to you if your like to check out the set up.

Ranger

 

It should run to the back of the transfer case, not the transmission. There is a cable actuated drum brake that clamps the driveshaft instead of wheels. Standard D18 stuff.

 

I too believe mine is on the tranny and not the t-case. Will have to look and confirm.

MM

 

The problem with the Driveline E-brake that I've had is that somewhere the cable system binds. Have replaced the cable twice in 1 year (second time the cable broke) and currently have to get out of the Jeep to achieve any purchase to pull the handle and then the e-brake only just engages. When the cable goes in new, it works fine for about a month.

Anyone with an idea for keeping the brake/cable free? Any special lubrication points?

Thanks,

Douglas..

 

check your electrical grounds.i have seen were a faulty ground would cause the ground path to go thru a cable such as the e-brake,trans shifter,throttle cable.just something to checkout.

mike s.

 

Until the transfer case starts leaking at the output shaft seal.

 

But your comparison there is the torque of the engine on the brake. Not the brake holding the vehicle. In that circumstance yes it will be stronger because you dont have the additional torque of the rear end 5.38 x whatever you had before. So if you had your ebrake on the axle you would have undoubtly been able to turn the wheels over due to the extra torque. Both set-ups work, I think most of the people that run the driveline brake either do it because its stock or because they swapped to disk brakes in the rear and didnt go to the trouble of hooking up an ebrake system on it or they didnt have an option to do so.

 

I agree with the comment that the e-brake will hold statically when coated with a bit of oil from the rear seal.

View attachment 15714

I have since replaced the seal, and with the cable working, the "oiled" e-brake was solid.


Douglas..

 

Ive NEVER used mine , it worked when I built the jeep 2 years ago....................

You know at windrock when I was unloading my jeep , if I would have used the parking brake it would have never star........................... NM R)

Yall that were there remember R) R) R)

 

there are plans for converting the xfer drum brake to a disk.

after looking at your pictures, jason, your ebrake is indeed attached to your tranfer case as it's supposed to be.

from the images john (aka panzer) posted you can get an idea of how it works. to adjust it, i had linings just touch the drum and tahen backed off about 1/4 to a 1/2 turn. if you don't already have one, i would suggest you get a factory service manual reprint (FSM) that covers your year and model.

nice looking project! enjoy it.

btw, my last experience was that herm prefers to sell/ship the entire drum, brake, and backing plate assembly and them use your old pieces to apply for partial or full core price depending on how much of your original you send back.

 

I rebuilt the T-case when doing the SM465 swap. Make sure you use some sort of sealant on the output shafts to help reduce leaking. I still have a very minor leak but much less than before. I used black silicone when reassembling.

I also opted for a disc conversion instead of the drum. I found using a foot lever instead of hand lever gives much more pressure when needed.

 

Thanks for all of the great advice. I like the idea of a disk brake conversion, but I also want to try and keep to original equipment. I have not even looked at it at this point. I have been putting all of my efforts into getting it road legal (which finally happened today!) Now I can take a look at that thing and see just how it works.

On this issue, my 1970 still has that hand lever to use the brake, if i so desire... can i use the foot lever out of a later model CJ5 located in a locall junk yard and easily install it into mine?