ok so i have the big ass dana 70 with drums, now i was originally gonna put some disks on it and got to thinking with mr sillyneck about the dana 300 pinion brake jesse makes, if i took the drums off and added one of those pinion brakes with a regular caliper rather than a cable actuated one this woul dact as my rear brake right? now lets see why this is good and or bad. thanks guys! jiMMy

Maybe it would work with one huge rotor and caliper. but the little rotor and little caliper wouldn't work so well by itself.

It would over heat real quick I imagine.

HUMMM. I was planning on talking to Jesse about this same thing but I want to use it as a cutting brake. I think it would not work well for any street driving because it would over heat. But a trail rig it might be OK on.

I was thinking about the same thing. Besides the heat and upgraded rotor and calipers size i was a little concerned with the torque placed on the back of the t-case every time you stepped on the brakes. That is gonna want to twist the tailshaft housing everytime the caliper is applying pressure.

EEEWWWHHHHH Didn't think of the torque.

How much more torque would be produced with braking with this setup versus excelleration with a built motor and very low gears?

Originally posted by Monkeyboy
EEEWWWHHHHH Didn't think of the torque.

How much more torque would be produced with braking with this setup versus excelleration with a built motor and very low gears?

it would be the same as your rear end ratio. so if you had 5.38s it would see 5.38 times the torque.

i would just stick with the wheel brakes if i were you.

Lose a drive shaft or two and lose your brakes.

Could leave you with some interesting winching from the spot you broke on.

The Fat City Bronco has s imilar set up, you might try getting in touch with those guys.

pinion brake would work fine as a main brake ,,,,if you had 4:10 gears then you would have 4 times the brake power, devided by two for the original two bakes and you still have twice the power. but you would want a spool or at least a locker, otherwise your really only stopping one tire

If you don't have a spool or locked ARB, a jab at the brakes will stop ONE tire ONLY. (think cutting brakes on the freeway):eek:. Even a detroit will allow one tire to overrun the other, they just don't let one go slower than the driveshaft speed....

Gonna jump in here and get flamed, but I keep thinking that the physics of this are not related to gear ratio.

Seems to my warped thinking that brakes turn rotational energy into heat. Regardless of where the brake assembly is in the mix - you have X amount of energy to absorb, and Y amount of braking capability to do it.

A pinion brake is going to absorb the same amount of energy as two rotors or drums, either way. The gear ratio does not figure.

What am I missing?

well if you think about it under a load torque is being multiplied but speed is cut so a pinion brake would see a rotor that spins x times fater than the wheel (x being gear ratio) but with x times less torque but dduring a braking situation the drive train is not recieving torque application but of load outside the breaking area is at the wheel it be the weight of the vehicle at a certain speed including rotational forece of wheel and tire where at the pinion it would be stoping the rotational inertia of wheel tire axle shaft gears and driveshaft. but i could be :smokin: :flipoff2:

I just think it would suck for two reasons:

1) It would put your driveshaft through hell, especially during emergency stopping.

2) I would think it would wear out your output shafts bearing much quicker, and perhaps under certain circumstances break your output shaft due to te weird direction force that would cause...

I have to agree with a few others here and unless you had a locked rear you could be asking for real problems if you were to do a panic stop on wet pavement or if one wheel looses traction you've lost your brakes.

Also you have to figure that you're single caliper and rotor is going to have to absorb and disperse the energy normaly done by two rotors and four pads.
Aslo if you're runing 4.11 gears your single brake is going to have to work four times as hard since the rotor's going to be spinning four times as fast.

He has a welded........I mean spooled rear end. I wouldn't do it though Jimmy, disc the 70

Transfer case brake good for e-brake. Disks on the big arsed 70 good for street use. C-ya on fordyce:flipoff2:

matt-