Every vehicle has a weak point. There is always some piece or point in the vehicle that fatigues or breaks faster than the rest of the machine. For the Polaris RZR, the weak point is often times the plastic roller cage assembly in the front differential. This plastic cage is not so much a purposely-designed weak point, but more an economical choice seen as being sufficient enough to handle the average consumer's general use. That makes it fine for gentle driving, but some more "enthusiastic" off-roaders have found it insufficient during more extreme UTV use. Since we're sure you read the Polaris manual cover to cover, you know that it states that AWD should never be engaged while at high RPM or when the rear wheels are turning. Although this may happen, the damage more commonly occurs when the front tires spin and then quickly catch traction.
DragonFire witnessed the weak, plastic front roller cage wreaking havoc on the RZR's AWD functionality and fabricated a replacement assembly from lightweight, durable 6061 aluminum. While DF's billet piece makes for a superior repair, it is also makes a great, proactive replacement. It will help ensure that you won't be stranded in 2WD when AWD becomes a necessity. Since we'd never ripped the front diff of our RZR open before, we enlisted the help of Dennis Gregory at Xtreme Unlimited in Oceano, California.
 |  Replacing a broken or worn...  Replacing a broken or worn front roller cage assembly is quick and easy. The hardest part is removing the differential from the RZR frame. The lower arm's ball joints need to be unbolted so that the axle shafts can be removed. This allows the differential to then be finessed out of the frame. The long travel kit that was previously installed on the RZR forced the guys at Extreme Unlimited to unbolt one of the upper arms from the frame in order to slide the differential out. |  The RZR uses a Hilliard Centralized...  The RZR uses a Hilliard Centralized Front Differential to provide power to the front wheels. The roller cage is seated inside the clutch housing ring gear and keeps all the rollers in line. When the AWD is disengaged, the cage and rollers keep the ring gear rolling smoothly on the output hubs. When the AWD switch is flipped, a magnetic actuator powers on and holds an engaging ring in place. The engaging ring holds grooves in the top of the roller cage to stop it from turning. Opposing motions then lock the ring gear, roller cage, and output hubs together with friction. |
 Surprisingly, the plastic...  Surprisingly, the plastic roller cage in our differential turned out to be intact, meaning we had a problem somewhere else to find. Even so the cage assembly wasn't broken, this is usually the first part to fail in the front differential. It is a good idea to replace the stock sprague before it breaks, so no other differential internals are damaged when it lets go. Note that the rollers are pushed against the ring gear wall with H-springs. When removing the cage from the ring gear, the rollers are going to want to pop out of the assembly once the gear housing is cleared. After checking the rollers and springs for wear and other damage, they will be reused in the new DragonFire Racing cage. |  When you take out the original...  When you take out the original plastic cage and install the new one, pay attention to nonsymmetrical markings. Here you can see the vertical grooves on the new DragonFire Roller Cage. The vertical groves go inside the clutch housing ring gear on the toothed side of the gear. This billet piece looks so nice it's a shame that it will be hidden inside the differential. | |