Many pictures were provided by patparts.com – Check them out if you are interested in pinion brakes!
What is a pinion brake?
A pinion brake is a special type of brake that will help your vehicle brake at a differential. Instead of using a master cylinder pushing fluid onto multiple cylinders in calipers and drums on all 4 corners of the vehicle. A pinion brake is mounted on top of the differential, Much like a standard brake system, it will use a brake caliper, rotor, and brake pads.
The biggest advantage a pinion brake offers is a multiplied braking power factor. Since a pinion brake is mounted to the differential, it can use the same gearing your engine, trans, and TC utilizes. Both cases now, either accelerating or braking will be utilizing your gear ratio.
Rock crawlers also benefit from any weight reduction they can get. Add weight reduction and increased performance together, it becomes confusing why pinion brakes are not more commonplace. Unfortunately like everything, Pinion brakes have drawbacks.
It is true that pinion brakes will stop you faster than drum brakes, but they also have several disadvantages that I’ll discuss at the end of the article.
Who should use pinion brakes?
Rock crawlers benefit from pinion brakes. Those who run Rockwell axles, planetary axles, and even one-ton axles could benefit from pinion brakes.
By far the easiest way to run pinion brakes is with 2.5-ton Rockwells and planetary gear axles just because they come factory optioned with these accessories. Do not let this stop you from looking into pinion brake options for your dana 60’s.
Jake Burkey is the industry expert. For any information you need for your crawler or jeep visit: https://bustedknuckleoffroad.com/
Are Pinion Brakes Street Legal?
No, in almost all states it is not legal to run only pinion brakes for your vehicle. I can assume this is due to some notable issues pinion brakes face. I want to make a distinction here. Having illegal brakes will not get you pulled over and arrested on sight. I doubt most cops will even notice the difference between having drum brakes and pinion brakes. Not my call nonetheless, do your research.
I would also go as far as saying pinion brakes, kind of like full hydraulic steering will get into the category of “we have done it this way for years, and now its law.”. In the case of full hydraulic steering most states, cities, and municipalities will require a physical-mechanical linkage between the steering wheel and the drive tires.
My point of view is, hydraulic steering could be more reliable and also add value to a steering system compared to that of its mechanical linkage brother. I won’t get too far off into the left-field on this, but technically the cylinder makes a mechanical linkage between the drive tires. Even with a single-ended cylinder, your tie rod will remain in place connecting the drive tires. The only difference is instead of a steel rod connecting the steering wheel to the steering gearbox, hydraulic lines would be in place. If we want to get extremely technical, we could run a steel rod from our steering wheel to an orbital that is in place of a standard steering gearbox. Yet this still wouldn’t be considered legal in most states.
This is not to say pinion brakes do not have problems they face. Let’s cover those issues now:
What issues are there with pinion brakes?
Pinion brake high temperatures:
Braking component temperatures will most definitely increase compared to brakes on all 4 corners of a vehicle. Yes, pinion braking is a great increase in performance over its counterpart. But like all things in life, increased performance typically equals increased heat. Combine that with deleting half the brake rotor surface to dissipate heat and we have a true problem on our hands.
The largest heat generation will occur when the brakes are not being applied. Since a pinion brake is using the axle gearing as mechanical advantage, this also means the rotor is spinning extremely fast; all the time. Even when the brake pads are not contacting the rotor surface, the rotor will still heat up. At this point, the rotor becomes quite literally a heat transfer surface. This is good for your axle gears, imagine you just added a heat sink to your gears. This is awful for your braking system. When considering pinion brakes, you must also consider high-performance slotted rotors that can quickly and efficiently dissipate heat.
As far as heat generated from brakes contacting the rotor unless you plan to auto-cross this vehicle, or maybe try to roll the dice of braking legalities. You will be just fine with as much offroad you can handle before we see any notable differences comparing the stock systems. If you’re interested in pinion brakes for an offroad dedicated rig, this example of heat problems will not be an issue.
What would happened if I break an axle with pinion brakes?
Yes, you will lose half the braking capacity as you did before this event. Remember both axles have a pinion brake. Take this next statement with a grain of salt, because it is an opinion of mine. I would go as far as to say a single pinion brake on an axle has an equal amount of stopping power as the stock braking system on all 4 corners.
Another point to make is if you break an axle shaft. Braking force tire that tire or tires will be lost. This example will hold true even when your axle is in an unlocked position.
Now if we are speaking of both axles having catastrophic failures at the same time. Then yes, all braking systems will fail at this time.
Another notable mention for potential pinion brake problems is a pinion brake applies some pressure to the coasting side of the pinion/ring gear, which is also referred to as the weak side. – Dean Ryan
Does the axle need to be locked for a pinion brake to work?
Contrary to popular belief, the axle does not need to be locked for braking power to work effectively. When the axle is in an unlocked position, the axle shafts that are being driven at the time by the differential will receive braking power. This could cause an issue with parts not holding up to the load previously handled by both axle shafts. At the very least while the axle is in an unlocked position your braking capacity will be cut in half.
Many say they experience vibrations when the axles are not locked together. This is with good reasoning too, anytime you add a rotating mass that is probably unbalanced, it will cause vibrations.
Are pinion brakes touchy?
Yes, pinion brakes are very touchy. They have a great learning curve when trying to understand the amount of force to press on the brake pedal to achieve the result they desired. Some go as far as adding air to brake lines just to soften up the pedal and make it more manageable. Could you imagine? A brake situation where you must un-bleed brakes to be comfortable. Pinion brakes have been referred to in the past as “an on/off switch”.
Advantages of using a pinion brake
Pinion brakes offer more control
The thing about pinion brakes is that they allow you to stop quicker than any other alternative. The exact moment you would like to stop is the exact moment you will stop. The absurd power offered from a pinion brake is unmatched for offroad vehicles.
While you will encounter a learning curve with pinion brakes, both the operation and the specific design for your crawler. These will allow an overall substantial increase in control. Not even to mention the added benefits of almost 50 pounds per side of an axle in weight reduction.
Are pinion brakes less expensive?
Your average pinion brake costs somewhere between $200 and $300. Sure, that doesn’t sound like a 50% discount or anywhere near it, but you’re still saving money in the long run considering you only have half as many calipers, rotors, and brake pads to service.
Pinion brakes are not for everyone, though – and cost shouldn’t influence your decision to get them.
Are pinion brakes dangerous?
Are pinion brakes inherently dangerous? Not at all!
Are pinion brakes dangerous to drive in the city? Yes, they are.
Off-road pinion brakes are no more dangerous than brakes on all four corners. In most cases, pinion brakes will increase the safety of others and yourself.
Using pinion brakes on the streets is dangerous – but not for the reasons you think.
The thing about these brakes is that they generate a lot of heat. And when I say a lot, I’m talking about six to seven times more than your average brakes. Now, that much heat is nothing to worry about at low speeds; anything less than 30 MPH. On the city streets, things change. You have to constantly brake, hit the gas, switch gears, and on and on. Your pinion brakes will overheat.
How much do pinion brakes cost?
Buying a pinion brake could set you back $200 or $300. Alternatively, drum brakes on 2.5-ton Rockwell axles will touch the realm for $500 per corner. Unlike other alternatives, you don’t need to buy both the front and rear pinion brakes to use them, you can install one on an axle alone if you want to.
There are more expensive pinion brakes out there as well as cheaper ones. On average, you’ll spend $250 for a quality set.
My honest advice would be to not look for a cheaper alternative! If there’s something you shouldn’t try to save money on, that’s brakes.
You can put some extra money and get premium pinion brakes – but that’s not an absolute must.