A rear knuckle is the part that ties your wheel, bearing, trailing arm and radius arms together on a Polaris RZR XP 1000, and when a stock cast knuckle cracks you aren't limping home, you're towing home. These billet rear knuckles replace the factory pieces with machined 7075-T6 aluminum that has close to twice the yield strength of stock. They bolt up to the 2017-2023 XP 1000 and XP 4 1000 and come as a left and right pair.
Highlights
- Machined from 7075 billet aluminum
- Virtually two times stronger than factory knuckles
- Compatible with stock and aftermarket suspension and with stock wheel bearings
- Matches stock geometry for a straight bolt-on install
- Includes left and right rear knuckles
Why a Broken Knuckle Matters
Few failures end a ride faster. A cracked spindle at speed, with trees going by on both sides, can turn into a wreck instead of an inconvenience. The rear knuckle on the XP 1000 takes every hit the rear tire takes, plus the leverage from bigger, heavier wheels and tires, so it's a smart place to add strength before something lets go.
Nearly Double the Strength of Stock
The factory knuckle is 6061 aluminum, which has a yield strength around 40,000 psi. These are cut from 7075-T6 billet, rated at about 73,000 psi, close to double. In practice that extra margin means you can keep your foot in it longer, take bigger hits and jumps, and stop worrying about the rear corners every time the machine lands hard.
Bolt-On Fit with What You Already Run
The knuckles work with any suspension you have, whether it's stock or aftermarket trailing arms and radius arms. They accept the stock wheel bearing, so service and replacement stay simple and parts are easy to find. Geometry matches the factory knuckle exactly, so alignment and handling don't change. Material that wasn't doing any work was machined away to give the suspension more clearance, and the billet finish looks sharp behind the wheel.
What's in the Box
- Left rear billet knuckle
- Right rear billet knuckle
Who It's For and What Pairs Well
These are for 2017-2023 owners running larger tires, aggressive trail speed or desert riding where the rear end takes a pounding. While the hub is apart, it's a good time to put in fresh bearings and stronger links: see rear trailing arms and radius arms in RZR XP 1000 suspension parts (4-seat: RZR XP 4 1000 suspension parts) and heavy-duty axles in RZR XP 1000 axles and CVs.
Fitment
| Year | Make | Model |
|---|---|---|
| 2017-2023 | Polaris | RZR XP 1000 |
| 2017-2023 | Polaris | RZR XP 4 1000 |
Replaces OEM Part #'s: 5140634 & 5140635
Installation Notes
The knuckles replace OEM parts 5140634 and 5140635 and reuse your stock wheel bearing. Plan on pressing the bearing into each new knuckle. Follow the installation guide below for torque values.
- source:
- superatv
- satv_url:
- https://www.superatv.com/polaris-rzr-xp-1000-billet-rear-knuckles
- fitment_raw:
- Polaris RZR XP 1000 2017-2023; Polaris RZR XP 4 1000 2017-2023
- install_pdf:
- https://madmin.superatv.com/amfile/file/download/file/5031/product/26064/
- desc_status:
- rewritten_2026-10-23
