Spicer. In good ol' Pa. you must have a service brake at each wheel for State Inspection. That eliminates pinion brakes for street use in Pa. I'm running pinion brakes on my newest project, But as you well know, that is strictly off-road. The only problem with pinion brakes occurs when you are not running a locker or welded rear. Under a hard braking situation, if one wheel is on a hard surface while the other wheel is on a slippery surface. If you are hard on the brake , and one wheel has alot less braking traction then the other one, the differential will then take over and let the wheel with the least traction turn backwards. While this is a very unlikely situation, it can happen. M1028