Messing With And Modifying The Gearing Of A Polaris RZR

Dec 15th 2019

There are various reasons why riders choose to replace or modify the gearing in their Polaris RZR. In particular, Polaris RZR gear reductions are commonplace, as they give the machine a good deal more torque and allow it to handle large, aftermarket tires. Mud-specific UTVs as well as RZRs that are used for rock crawling and hill climbing will also benefit from gear reductions. But when it comes to gear reductions for the Polaris RZR, there’s more than one way to skin a cat. Be it a 27% gear reduction coupled with a Duraclutch for the perfect crawler vehicle, or a 30% gear reduction with 4-inch portals for a beastly mud machine, here’s the low-down on Polaris RZR gear reductions. 

Gear Reduction Kits For The Polaris RZR

As one of the go-to side-by-side companies for aftermarket Polaris RZR parts, SuperATV’s 25% gear reduction kit for the Polaris RZR is a good path to take if you’re a slow roller who uses the RZR to traverse rocks and ascend hills. This particular gearing is great for running 30-inch tires and above, with an ample amount of torque to spare. As a matter of fact, it might actually be too steep of a gear for many riders, causing them to blow tires off on the rocks and loose traction when too much is applied to the throttle. However, with a proper tune to make the gear reduction less aggressive, this high-range Polaris RZR gearing setup is absolutely wicked. And if your budget is tight and you’re looking to save a bit, you can order used OEM Polaris gears instead.

The REV 1 Crawling Kit is another gear reduction kit for the Polaris RZR and Polaris RZR 4 that will make a big difference in your ride — knocking your machine’s low in half. It is pretty easy to install and works well with a decent clutch kit — like the Dalton Clutch — but can also work with the stock RZR clutch, RZR Turbo clutch, and RZR 4 clutch. Other kits are available to attain a variety of gear reductions in the RZR, such as 21% Low range only; 33% Low range and 12% in Reverse and High; 47% Low range and 26% in Reverse and High; and 47% Low range, 26% in Reverse, and 12% in High. Most of the gear reduction kits out there will include the necessary gearing for the specified ratios, an HD Reverse chain and sprocket, and one new bearing for the clutch side of the input shaft.

Swapping In OEM Polaris Gears

If you want to do a gear reduction in your Polaris RZR by swapping in factory Polaris gears, start by comparing the transmission case on your buggy with the transmission case of the Polaris 570 or Polaris ACE. If both vehicles take the same case, then the 570 or ACE reverse shaft and gears will work. Typically, the 570 is a 14% reduction and the ACE is a 27% gar reduction. On the 2018 RZR XP4, there are two transmissions, while there is only one in the regular XP4’s and the Highlifter XP4. 

The Highlifter XP4 has the same reverse shaft and gear as the 570. So that’s a good route to take if you own the Highlifter XP4. The Regular XP4 rev shaft (part number 3235224) has twenty-nine teeth, while the gear (part number 3235229) has forty-four teeth. On the Highlifter XP4 and 570 XP4, the rev shaft (part number 3235380) has twenty-seven teeth, while the gear (part number 3235381) has forty-six teeth. Finally, if you want the 27% ACE 325 gear reduction, you’ll need the twenty-five-tooth rev shaft (part number 3235451) with the forty-eight-tooth gear (part number 3235450).

No matter which gearing you choose to throw into your Polaris RZR, you will gain significantly more torque, which will increase your riding capabilities on steep trails and when rock crawling. Yes you might loose some top-end speed in low gear (for example from 38mph to 30mph at max power band with the 27% reduction) but sacrifices are always involved when you modify a stock UTV. 

If you go this route and buy the gears instead of a complete Polaris RZR gear reduction kit, you might want to also go ahead and do the reverse chain and get a thicker pinion plate. And while you’re at it, an aftermarket clutch like the 3P will also bring countless benefit to you and your ride. And even if you aren’t a hill climber, mudder, or rock crawler, a Polaris RZR gear reduction will also help to reduce ware on your belt and save your axles.

Because the XP4 gears are reduced by 12.5%, they will give you enough torque to crawl, but won’t hurt your top end too much so you can still rip it up at the dunes or on the track when you feel so inclined. The 24% gear reduction is great, and will make controlling the throttle much easer when crawling and improve the machine’s climbing ability, but your RZR will lose some speed off the top. For this reason, the 12.5% reduction is a healthy medium. The top speed will likely go down to 68mph from 72mph, but the advantages in the lower end will make a world of difference. 

Summing Up

The terrain you ride will ultimately determine whether or not you need a Polaris RZR gear reduction. If you think you’ll need lower gearing and have yet to pop on an RZR, you should look into the RZR Trail and Rock Edition. Add that model plus a throttle mapping tune for low gear and you’ll climb anything you point your RZR at. A gear reduction comes standard on the factory Trail and Rock Edition, and it's advertised as a 55% reduction to deliver a max speed of 20-25mph in low. Add a tune for more throttle control in low if you feel like you'll need it, but you may not have to as Polaris really nailed it with their Trail & Rock Edition.