Polaris Ranger XP 900 ball joints fail at the snap ring, and a work machine finds that weak point faster than a sport car does. Loaded beds, towing and long days on rough ground put steady load through the front end, and that thin retaining clip is all that holds a factory joint in the A-arm. 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 Ranger XP 900 and the Ranger XP 900 Crew. 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: Ranger XP 900 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 on rough ground and washboard
- Play in the wheel when rocked top-to-bottom on a jack
- Repeat joint failures on a machine that hauls, tows and works loaded
- Torn boots admitting water, mud and grit so the joint wears from the inside
- Downtime on a machine that has a job to do
Best For: Working and Loaded Ranger XP 900 Machines
- Ranger XP 900 and XP 900 Crew owners who work the machine rather than park it
- Property, ranch and job-site use with a loaded bed or trailer
- Owners running larger tires than stock
- Anyone who has already replaced a factory joint more than once
- Riders refreshing a high-hour front end on a machine they intend to keep
The Ranger Mega Keller joint is stronger still, but requires machined A-arms. This standard version threads into the factory arm as it sits.
Specifications
- Material: 4340 hardened chromoly steel, stud and housing
- Design: two-piece threaded housing, no snap ring
- Serviceability: adjustable, greaseable and rebuildable
- Boot: robust retaining ring to keep water and mud out
- 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-RG#AJ (one joint), BJK-P-RG-K-2#AJ (two joints), BJK-P-RG-K-4#AJ (four joints)
Fitment
- Polaris Ranger XP 900: 2013-2019
- Polaris Ranger XP 900 Crew: 2014-2019
Note that the Crew enters the fitment a year later than the standard cab. Fitment is not guaranteed on applications not listed above.
FAQ
Why do Ranger XP 900 ball joints pull out of the A-arm?
The factory joint is retained by a snap ring seated in a groove. The steady load a working Ranger puts through the front end 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 these fit the Ranger XP 900 Crew?
Yes, from 2014 onward. The standard cab is covered from 2013, so the Crew starts a year later.
Do I need different joints for the upper and lower positions?
No. On the Ranger XP 900 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 the boot any better than stock?
Keller uses a robust boot retaining ring specifically to keep water and mud out, which matters more on a Ranger than on a sport car because the machine spends its life in exactly that.
Do Keller ball joints require A-arm modification?
Standard Keller joints do not — they thread into the factory arm as supplied. The Ranger Mega version uses an oversized housing and does require machined A-arms, which is the main reason to pick one over the other.
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.
Keep Your Ranger XP 900 Working
Before ordering, decide whether you are replacing a single failure or refreshing all four corners — the set of four covers a complete front end and is the usual choice on a high-hour work machine. 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. Tie rods and A-arm bushings are worth inspecting while everything is apart.
Installation Video
Official SuperATV installation walkthrough with Todd Keller: How To Install Keller Ball Joints
