How to Replace Polaris Sportsman 850XP Front CV Boots

If you don't replace a damaged front CV boot immediately on a Polaris Sportsman, the CV joint will become worn and the repair will be expensive.

Even a small rip in a Polaris Sportsman 850XP front CV boot will let all the protective grease escape, which will allow dirt and crud to get in. This walkthrough shows you how to replace the front CV boot on a Polaris Sportsman 850XP ATV. 

Watch the video above to familiarize yourself with the front CV boot replacement, and print out this walkthrough for reference.

Tools and Parts Needed - Polaris Sportsman Front CV Boot Replacement


  • Ratchet and sockets
  • Hammer
  • Punch tool
  • CV boot pliers
  • Torque wrench


  • CV boot kit
  • Cotter pin

NOTE: You can purchase the parts for this job individually, but the OEM Polaris boot kit contains everything you need and costs less than buying the parts separately. 

Polaris XP Sportsman CV boot change

Installing Polaris Sportsman 850XP Outer Front CV Boot

Step 1. Remove the front wheel and the axle dust cap behind it.

Step 2. Remove the cotter pin, the axle nut, and the two cone washers beneath the nut.

Step 3. Tap the axle with a dead blow hammer to break it loose from the steering knuckle.

Polaris SPortsman 850XP front axle

Step 4. Remove the two 15mm brake caliper mounting bolts, and slide the caliper assembly off the brake rotor.

Step 5. Remove the 13mm upper A-arm mounting bolt, and pull the upper ball joint out of the steering knuckle.

Polaris Sportsman upper A-arm ball joint

Step 6. Remove the shock absorber mounting bolt from the upper A-arm, and use a bungee cord (or something similar) to support the steering knuckle.

Polaris Sportsman ATV shock absorber

Step 7. Tap the axle again with a dead blow hammer to push it through the steering knuckle. Then, use a punch tool and push the axle through further.

Polaris Sportsman 850 steering knuckle

Step 8. Release the bungee cord, drop the steering knuckle down, and pull the axle out from the back of the knuckle.

Polaris Sportsman ATV steering knuckle

Step 9. Remove the wheel hub and rotor assembly from the steering knuckle.

Polaris Sportsman 850 XP wheel hub rotor assembly

Step 10. Remove the two clamps from the CV boot, then slide the boot off the CV joint, cut the boot off and discard it.

Polaris Sportsman ATV front CV boot replacement

Step 11. Wipe away the old grease from the driveshaft and the CV joint. 

NOTE: Do not use brake/contact cleaner because it will get into the CV joint and dilute the grease inside it.

Step 12. Strike the inner part of the CV joint (where it meets the driveshaft) to remove the CV joint from the driveshaft.

NOTE: If you're also installing a new inner CV boot, you'll need to do that before continuing any further. See the Installing Polaris Sportsman 850XP Inner Front CV Boot section below.

Polaris Sportsman 850 CV boot removal

Step 13. Install the new innermost CV boot clamp onto the driveshaft before installing the new CV boot. Once the inner clamp is in place, slide the new CV boot onto the driveshaft.

Step 14. Pack the CV joint and the inside of the CV boot with grease.

Polaris Sportsman 850XP new front CV boot

Step 15. Align the CV joint with the splines on the driveshaft and tap it back onto the shaft.

Step 16. Pull the CV boot into the channels on the CV joint and the drive shaft. Make sure there is no grease on the channels, otherwise the connection between the boot and the CV joint and driveshaft won't be secure, and the CV boot might slip off.

Polaris Sportsman 850XP front CV boot channels

Step 17. Install the outer CV boot clamp, and use a pair of CV boot pliers to tighten the inner and outer CV boot clamps.

Polaris Sportsman ATV CV boot clamps

Step 18. Slot the axle back through the steering knuckle.

Step 19. Reinstall the shock absorber into the upper A-arm and tighten the mounting bolt.

Polaris Sportsman shock absorber install

Step 20. Lift the steering knuckle, drop the upper ball joint back into the steering knuckle, and reinstall the upper A-arm mounting bolt.

Polaris Sportsman upper ball joint

Step 21. Grease the inside of the wheel hub, and tap it back into the steering knuckle.

Polaris Sportsman wheel hub

Step 22. Reinstall the two cone washers so that their raised center sections are facing outward. Then, reinstall the axle nut.

Polaris Sportsman front drive shaft boot replacement

Step 23. Slide the brake caliper assembly back over the brake rotor, and reinstall the two caliper mounting bolts.

Polaris Sportsman ATV brake caliper assembly

Step 24. Have someone engage the brakes, then torque the axle nut to 80 foot-pounds. Install a new cotter pin.

Polaris ATV axle nut install

Step 25. Reinstall the front wheel.

Installing Polaris Sportsman 850XP Inner Front CV Boot

You can install a new inner CV boot with the driveshaft still attached to the Sportsman. Replace the inner CV boot using the same method as the outer CV boot. 

NOTE: The inner and outer Polaris CV boot kits are slightly different. Get the OEM Polaris inner front boot kit, and use the inner boot parts diagram for additional reference. 

Step 1. Remove the CV boot clamps and cut away the old boot.

Step 2. Wipe away the old grease from the inner CV joint and the driveshaft.

Step 3. Pack the CV joint and the new inner CV boot with grease, and slide the CV boot up the driveshaft and into the channels on the CV joint and the drive shaft.

Step 4. Install and tighten the new inner and outer CV boot clamps and you're done.

Polaris Sportsman 850XP inner front CV boot

Kit, Boot

Kit, Boot







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