Newbie with question about transmission brake

[purzell]

Hi, I'm new to the forum but have been reading and researching here for a while. I'm currently shopping for a truck and went to see one 1966 GMC that has a transmission brake. I can't find much if any info about this type of brake except for in this person's thread:

http://67-72chevytrucks.com/vboard/s....php?p=4958220

I know Google is my friend but there must be a name for this brake other than transmission brake because I'm generally good at finding info online but not in this case.

Any leads are appreciated--want to know how this brake works and what it does. Thanks!

[BMERDOC]

Use the term "trans brake" when searching. When you hold the button down it holds the trans between first and reverse. When you let go WHAMO!! off you go. You are either looking at a very hot truck or someone installed it thinking they were doing something big. It usually requires a pretty stout drive train and rear suspension and is the next step up from foot-braking. A serious reduction in 60fts. I know other people will chime in but those are the basics.

[purzell]

Thank you...did any particular model come with that brake stock in the truck? I'll have more info when I connect with the gentleman again but he called it a "Longhorn" model (which name I have not found used for this age truck) and stated it came with that brake. DMV confirms the truck is (at least registered as) a 1966.

[tincan1966]

he may be referring to the park brake configuration that some trucks had on manual trans. It was basically a drum brake setup on the output yoke of the trans where the driveshaft bolted on. Usually see this is C-40 and up series trucks, but who's to say it wasn't swapped in later.

[purzell]

Thanks, if I get this truck I will post up some pics of the set-up. The guy has no phone so it's been a patience game working with him.

[tincan1966]

I went to the link you showed. It is a park brake setup,nothing too exotic. it is actually a way better park brake than using the rear wheels in my opinion.

[BMERDOC]

Originally Posted by purzell

Thank you...did any particular model come with that brake stock in the truck? I'll have more info when I connect with the gentleman again but he called it a "Longhorn" model (which name I have not found used for this age truck) and stated it came with that brake. DMV confirms the truck is (at least registered as) a 1966.

Originally Posted by tincan1966

he may be referring to the park brake configuration that some trucks had on manual trans. It was basically a drum brake setup on the output yoke of the trans where the driveshaft bolted on. Usually see this is C-40 and up series trucks, but who's to say it wasn't swapped in later.

Ok yeah, that make a lot more sense. IIRC, the trans-brake was introduced in the early 70's and is a drag car setup. The brake I was refering to woulda never been installed in a stock car much less a truck. In my mind someone shoulda built that car on an assembly line though Imagine if we didn't have the 70's-80's performance gap?

[purzell]

Tincan1966, thank you. I feel better knowing that it's not something exotic; hack jobs spell trouble to me. Thanks guys.

[HEI451]

It is the "emergency/parking" brake, on the back of the trans, as there are NO parking brake parts in either rear drum brake. It is a good brake, and it makes swapping rear discs, and other differentials into the trucks easier. My 1964 C30 1 ton dually flatbed has one, I like it.

[cb1965]

I saw this floor ebrake setup in a '63 c20 at picknpull. Is this a desireable set up? I had never seen one. Didnt think to get pictures.
Posted via Mobile Device

[Notch1988]

My truck started out as a 930 and has the tranny mounted park brake. I'd like to use it when I do an LS swap cuz I think it's cool cranking back on that big lever.

[Captainfab]

I've seen the trans mounted parking/emergency brakes on C30 and bigger trucks. However they were available on the C20's also. This style of parking/emergency brake was also used in motorhomes on the back of the TH400's

[HEI451]

My neighbor's 1968 Dodge dump truck with 5 speed in it has one, and it works like mine, great. I like this kind of parking brake much better the ones at the wheels. Over the 42 years time I have had building all sorts of hot rods and other cars, I've used this method in some of those cars that had the room for them, and I always liked the results. BTW, you DON'T have to run the floor lever, with a little ingenuity, a cable can be set up, from a dash lever or floor pedal to operate them.

Be creative, there's more than one way to do this stuff, the drum and band don't have to be in the back of the trans, there is another flange on the front of the differential. Anything is possible, just have to get out and think it up, then, just go do it.

[Bears63]

It's a pretty simple and effective parking brake, that's for sure. I love these just because it throws people off when they see the extra lever on the floor. Good for causing head scratching