How to Repair a CV Boot on an ATV 4-Wheeler

The CV joint relies on its boot for protection from the elements.

All-terrain vehicles rely on constant-velocity joints to ensure that power is evenly delivered to their wheels, regardless of the riding environment or steering inputs. The CV joints are protected by rubber boots that prevent dirt, rocks and other harmful debris from damaging the joints, as well as containing the grease that the CV joints need to move smoothly. The CV boots are often subjected to harsh conditions, often leading to a rip or tear that can allow the joints' supply of grease to leak and let debris into the sensitive CV joint. Since the flexible rubber cannot be repaired permanently, replacement is the best solution.

Things You'll Need

• Pliers
• Ratchet
• Socket set
• Jack
• Bungee cord
• Tie-rod puller
• CV boot clamp pliers
• CV boots
• Molybdenum-based grease
• Boot clamps
• Wheel hub cotter pin

Instructions

1. Inspect the ATV's CV boots, located between the front wheels and the front differential. If the boot is torn, ripped or punctured, it must be replaced.

2. Remove the cotter pin from the nut at the center of the wheel hub, using pliers. Loosen the hub nut, the lower front shock absorber bolt and the lug nuts, using a socket wrench.

3. Lift the wheel off of the ground, using a jack placed under the ATV's frame. Remove the lug nuts with the socket and ratchet and the wheel from the wheel hub. Remove the front brake caliper from its mounting bracket on the steering knuckle -- the pivot that attaches the front hub to the frame-like A-arm -- using a socket wrench. Hang the brake caliper from the ATV's frame, using a bungee cord. Unscrew the hub nut completely and pull the hub off of the CV joint assembly.

4. Remove the lower front shock absorber bolt and separate the shock absorber from the A-arm. Remove the steering knuckle tie-rods, using a tie-rod puller. Pull the steering knuckle away from the A-arm and the front axle. Pull the entire CV joint assembly out of the front differential.

5. Remove the clamps attaching the CV boots to the joint assembly, using CV boot clamp pliers. Pull the joint assembly apart and remove the boots from the joint shaft.

6. Fill the new CV boots with molybdenum-based grease, then slide the boots onto the joint shaft. Coat the joint shaft ends in grease and push the offset CV joints over the shaft ends. Slide the CV boots over the offset joint ends, then secure them in place with new boot clamps, using CV boot clamp pliers.

7. Push the CV joint assembly into the front differential. Push the steering knuckle over the free end of the joint assembly. Push the steering knuckle tie-rod shafts into the A-arm, then reattach the front shock absorber to the A-arm. Screw the lower shock absorber bolt into place.

8. Slide the wheel hub onto the CV joint assembly, then loosely screw the hub nut into place. Reinstall the front brake caliper onto the steering knuckle. Reinstall the wheel onto the wheel hub and loosely screw the lug nuts into place.

9. Lower the ATV to the ground. Tighten the hub nut, then the lug nuts to the manufacturer's recommended torque range. Alternate from lug nut to lug nut in a criss-cross pattern to evenly tighten the lug nuts against the wheel and wheel hub. Push a new cotter in through the end of the CJ joint assembly and the hub nut, then bend the pin's legs around the lug nut, using pliers.

Tips & Warnings

• CV joint and boot replacement instructions, as well as torque specifications, can be found in a factory service manual specific to your ATV.

References

• Yamaha YFM400FAR Service Manual; Yamaha Motor Corporation
• Honda TRX400EX Service Manual; Honda Motor Company