The Pro R makes more power than any RZR before it, and the factory ball joint is still held in by a snap ring. That ring is what gives. Keller ball joints delete it entirely — the two-piece housing threads into the A-arm like a nut and bolt, so there is nothing to shear and nothing to push out. Hardened 4340 chromoly, greaseable, adjustable and rebuildable.
Todd Keller's original threaded design, covering the Pro R and Pro R 4 from 2022 onward. Uppers and lowers are different parts here — buy one, a pair, or a full front-end set of four.
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
- Uppers and lowers sold separately, in pairs, or as a set of four
- Backed by a lifetime warranty
- Made in USA
Built To Solve: RZR Pro R Ball Joint Pull-Out Under Power
- Snap ring shearing and letting the joint separate from the A-arm
- Front-end clunk or knock that shows up after hard landings
- Play in the wheel when rocked top-to-bottom on a jack
- Repeat OEM joint failures on a machine putting down class-leading power
- Torn boots letting water and grit wear the joint from the inside
- Joints that have quietly become a routine replacement item
Best For: High-Horsepower Desert and Dune RZR Pro R Builds
- Pro R and Pro R 4 owners actually using the power the machine makes
- Desert and dune riders loading the front end hard on landings
- Riders on larger tires, added lift or portals
- Pro R 4 owners carrying more weight through the front end
- Anyone who has already replaced a factory joint once
If your A-arms are machined for oversized housings and you are building for maximum strength, look at the Mega Keller joints for your platform instead.
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: upper and lower are separate parts, sold individually or together
- Warranty: lifetime
- Manufacturer Part Number: BJK-P-XP1KT#PR (upper, one joint), BJK-P-XP1KT-K-2#PR (two uppers), BJK-P-RZRTR#AA (lower, one joint), BJK-P-RZRTR-L-K-2#AA (two lowers), BJK-P-RZRTR-K-2#AA (one upper and one lower), BJK-P-RZRTR-K-4#AA (two uppers and two lowers)
Fitment
- Polaris RZR Pro R: 2022 onward
- Polaris RZR Pro R 4: 2022 onward
Both the two-seat and four-seat Pro R are covered. Coverage begins in 2022 and remains open on current machines. Fitment is not guaranteed on applications not listed above.
FAQ
Why do RZR Pro R ball joints pull out of the A-arm?
The factory joint sits in a groove held by a snap ring. Under the loads a Pro R generates — especially landing hard or running bigger tires — that ring can deform or shear, and once it goes nothing is retaining the joint. Keller joints thread into the A-arm instead, so no clip sits in the load path.
Do these fit the four-seat Pro R 4?
Yes. Both the Pro R and the Pro R 4 are covered from 2022 onward.
Do I need uppers, lowers, or both?
Uppers and lowers are different parts on the Pro R and are sold separately, so you can replace only what failed. The set of four covers two uppers and two lowers for a complete front end.
Do Keller ball joints require A-arm modification?
No. These thread into the factory A-arm as supplied. Only the oversized Mega version requires machined arms.
Will they hold up to big tires and added lift?
That is the load case they exist for. Larger tires and lift increase leverage on the joint, which is exactly when snap ring retention is least forgiving. The threaded housing does not rely on a clip to stay put.
Can these be rebuilt instead of replaced?
Yes, and that is the design intent. 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 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.
Build a Pro R Front End That Matches the Engine
Before ordering, decide whether you need uppers, lowers or both, and select that configuration on this page. If a boot has split but the joint is still tight, the Keller boot replacement kit is the cheaper repair. If the joint is worn but the housing is good, the Keller rebuild kit for Polaris restores it. Riders putting real hours on a Pro R usually check tie rod ends and A-arm hardware while the front end is apart.
Installation Video
Official SuperATV installation walkthrough with Todd Keller: How To Install Keller Ball Joints
