He's pointing at it

I was watching top truck challenge and a lot of the Riggs have this thing what is it?

 

Looks like a brake disc for diff mounted brakes like you would see on heavy equipment or military stuff.

 

rockwell axle or 2 1/2 ton millitary axle

 

That's his brakes, they're mounted right on the axle. You can see how those axles are set up here: Red Barn Customs, 2.5 Ton Rockwell Axles, Mud Boggers, CNC Plasma Cut, Yale Mich

 

So, do they work as a secondary brake system or take the place of the clipper/drum style breaks?

 

Pinion Brake, if you look at current Top Truck Challenge mot of the competitors are running them. It's the only brake. One I read is using a Mazda caliper.



This is the most popular place these guys are getting their setups:
:: Ouverson :: Rockwell Pinion Brake Standard Rotor

 

Just cuz they are HEAVY DUTY or to cut down on bulk at the wheel? some of the TT guys are running 50in.+ tires

 

Being on the pinion the brake has a 4 to 1 (or whatever the differential gear ratio is) advantage over the wheels.

 

Weight is one reason (about 100lbs worth of drums etc.). Simplicity as well. You don't need a huge Master Cylinder either. One popular route is Mazda B2000 rotor and 1986 Toyota Caliper.

Just read this quote:

"That being said, I will tell you that even with 20″ military double beadlocks (with 5/8″ centers) and 53″ Michelin Tires, my rig would lock up all four tires easily! So for trail/offroad use I went with the pinion brake and have no regrets!"

 

See how the axle comes in at the top,

Will it still work with a hummer or unimog axle like the one

 

I think some vehicles put their emergency brake at the tail end of the transmission? This would be the same as braking the pinion.

Might not be DOT approved as the primary brake though.

http://api.viglink.com/api/click?for...%20Forums&txt=

 

Major problem with using a transmission tailshaft brake is that if you drop your drive shaft you've just lost your rear brakes. For off road only maybe that isn't an issue for you, but I doubt it would be smiled upon for on-road use. OTH, who's going to inspect it to know? OTOOH (on the other other hand) on-road it is more than just your *** on the line, it's all the people around you as well. Gotta stop now, I ran out of hands.