Polaris RZR RS1 ball joints fail at the snap ring, not the joint itself. That thin clip is the only thing holding a factory joint in the A-arm, and a single-seat car ridden the way an RS1 gets ridden will find its limit. Keller ball joints remove it entirely — the two-piece housing threads into the arm like a nut and bolt. Hardened 4340 chromoly, greaseable, adjustable and rebuildable.
Todd Keller's original threaded design, covering the RS1 from 2018 through 2022. On this machine the same joint serves both positions, so you simply choose how many you need.
Key Features
- Two-piece threaded housing eliminates the OEM snap ring
- 4340 hardened chromoly steel housings and studs
- Adjustable and greaseable for correct stud articulation over years of service
- Rebuildable — a worn joint is serviced, not replaced
- One joint fits both upper and lower positions on this platform
- Limited lifetime warranty against manufacturing defects
- Made in USA
Built To Solve: RZR RS1 Ball Joint Pull-Out and Snap Ring Failure
- Snap ring shearing and letting the joint separate from the A-arm
- Clunking or knocking from the front end over rough ground and whoops
- Play in the wheel when rocked top-to-bottom on a jack
- Repeat OEM joint failures on a light car that gets jumped hard
- Torn boots admitting water and grit so the joint wears from the inside
- Replacing the same joint often enough that it has become routine maintenance
Best For: Hard-Ridden Single-Seat RZR RS1 Builds
- RS1 owners riding dunes, desert and technical trail
- Riders jumping the car and landing it front-first
- Owners running larger tires than stock
- Anyone who has already replaced a factory joint more than once
- Riders rebuilding a front end who want to do it once
The RS1 shares its Keller joint with the Turbo S and Pro XP, so a single rebuild kit covers whichever of those you own.
Specifications
- Material: 4340 hardened chromoly steel, stud and housing
- Design: two-piece threaded housing, no snap ring
- Serviceability: adjustable, greaseable and rebuildable
- A-arm modification: not required
- Positions: one joint serves both upper and lower on this platform
- Warranty: limited lifetime against manufacturing defects, original purchaser
- Manufacturer Part Number: BJK-P-TSPR#RS (one joint), BJK-P-TSPR-K-2#RS (two joints), BJK-P-TSPR-K-4#RS (four joints)
Fitment
- Polaris RZR RS1: 2018-2022
This listing covers the RS1 only. Fitment is not guaranteed on applications not listed above.
FAQ
Why do RZR RS1 ball joints pull out of the A-arm?
The factory joint is retained by a snap ring seated in a groove. Hard landings can deform or shear that ring, and once it goes the joint has nothing holding it. Keller joints thread into the A-arm instead, so there is no clip to fail.
Do I need different joints for the upper and lower positions?
No. On the RS1 the same Keller joint serves both positions, which is why this product is sold by quantity rather than by upper and lower. Choose one, two, or a set of four for a complete front end.
Is this the same joint used on the Turbo S and Pro XP?
Yes. SuperATV uses one Keller joint across the RS1, Turbo S and Pro XP, which is also why a single rebuild kit covers all three. You are buying the correct part for the RS1 here.
Do Keller ball joints require A-arm modification?
Standard Keller joints do not — they thread into the factory arm as supplied. The Mega version uses an oversized housing and does require machined A-arms, which is the main reason to pick one over the other.
How many should I buy?
Ball joints wear as a set. Replacing a single failure is fine, but on a high-hour machine most riders do all four at once so the front end is consistent and they are not back under it in a month.
Can these be rebuilt instead of replaced?
Yes. They grease and adjust, and the Keller ball joint rebuild kit for Polaris services them with a new cup, boot and pin when the internals eventually wear.
Why Keller
Todd Keller designed the two-piece threaded ball joint to fix the one part of a stock front end that keeps failing, and SuperATV now builds and backs the line. The design has barely changed because it does not need to: thread the housing in like a nut and bolt, use a chromoly stud, and make the whole assembly serviceable so a worn joint gets rebuilt rather than binned.
Complete Your RZR RS1 Front End Rebuild
Before ordering, decide whether you are replacing a single failure or refreshing all four corners — the set of four covers a complete front end. If the boots are torn but the joints are sound, the Keller boot replacement kit is the cheaper fix. If the joints are worn but the housings are good, the Keller rebuild kit for Polaris services them. Riders doing a full front end usually look at tie rods and A-arm bushings while everything is apart.
Installation Video
Official SuperATV installation walkthrough with Todd Keller: How To Install Keller Ball Joints
