Anyone ever run a pinion brake?

[CherryK5]

I see them all the time on the 5 ton rockwells.
But that's off the drivshaft output.

Do they make a brake that would replace a pinion with a big fat disc brake on it?
I think that would be amazing and cool to have.
My dad's wrecker has one as an e-brake but i want one full time.

Any ideas? i might slice up a pinion to try and make one. =]

 

[tRustyK5]

From what I understand it's OK on the trail...however that pinion is spinning ~4 times as fast as the outers are, and there is only one disc/caliper. It'd have to be 8X stronger to match wheel brakes, and it'd get really hot really fast.

Rene

 

[Hogback Fabrication]

and it'd get really hot really fast.

Rene

That's the big thing, and balance issues, clearance issues etc. They work well on trail only stuff but they are not safe at all for a street driven vehicle.

 

[Blue85]

It'd have to be 8X stronger to match wheel brakes, and it'd get really hot really fast.

Rene

No. If you compare 1 pinion brake to 4 wheel brakes, the clamping force required is almost a wash. The differential ratio works in your favor, so if you had 4:1 gears, the force to stop the vehicle is about the same. You're right about the heat, though - because it has to do the work of 4 brakes, you'll need a massive rotor there - one that won't fit. Now if you're using pinion brakes front and rear, that's roughly half the force and twice the heat of a wheel brake.

However, I'm pretty sure the OP is talking about a parking brake, for which a pinion brake could work. The clearance at the pinion is a bigger issue than at the T-case, but it has the advantage that a broken driveshaft won't let the vehicle roll away. The clear candidates are axles with a bolt-on pinion, like the 14BFF, because that gives you something to attach a caliper to.

But I don't think there's enough clearance. Hit a rock, mess up the rotor and now your driveline is locked until you can go remove the caliper or rotor. You could put something like a "Guardsman" on there, but it would be so low...

 

[CherryK5]

No. If you compare 1 pinion brake to 4 wheel brakes, the clamping force required is almost a wash. The differential ratio works in your favor, so if you had 4:1 gears, the force to stop the vehicle is about the same. You're right about the heat, though - because it has to do the work of 4 brakes, you'll need a massive rotor there - one that won't fit. Now if you're using pinion brakes front and rear, that's roughly half the force and twice the heat of a wheel brake.

However, I'm pretty sure the OP is talking about a parking brake, for which a pinion brake could work. The clearance at the pinion is a bigger issue than at the T-case, but it has the advantage that a broken driveshaft won't let the vehicle roll away. The clear candidates are axles with a bolt-on pinion, like the 14BFF, because that gives you something to attach a caliper to.

But I don't think there's enough clearance. Hit a rock, mess up the rotor and now your driveline is locked until you can go remove the caliper or rotor. You could put something like a "Guardsman" on there, but it would be so low...

Damn clearance never crossed my mind.

But i want to add this in addition to the other 4 brakes not replace them.
And i kind of want it as a parking brake because when i do the disc brake swap i wont have a parking brake so it wont pass inspection.

 

[Hogback Fabrication]

Damn clearance never crossed my mind.

But i want to add this in addition to the other 4 brakes not replace them.
And i kind of want it as a parking brake because when i do the disc brake swap i wont have a parking brake so it wont pass inspection.

High Angle Driveline and probably others make a driveshaft mounted parking brake, it goes on the t-case side as to not inhibit clearance.

 

[Blazinaire]

what about adding another bracket at the wheel and running a separate mechanical spot caliper? Might still be cheaper than sourcing out caddy calipers or the like.

 

[dirtygoat]

I've thought about doing one on the t-case side of the rear d-line for a e-brake... Now I'm thinking more toward line locks...

 

[CherryK5]

I've thought about doing one on the t-case side of the rear d-line for a e-brake... Now I'm thinking more toward line locks...

How hard is running a line lock? and arent those electric? Or do they make a mechanical one?

 

[dirtygoat]

How hard is running a line lock? and arent those electric? Or do they make a mechanical one?

Pretty simple... There are both electric and manual... There's been several threads about them...