CV Boot Diagnosis and Replacement: 1995 Yamaha YFM350ER MOTO-4 Guide
Shop parts for a 1995 Yamaha YFM350ER MOTO-4 ATV.
Why Rear Boots Take the Most Abuse on a Work ATV
The rear CV boot on the 1995 Yamaha YFM350ER MOTO-4 seals the constant-velocity joint on the rear axle from the working conditions a utility ATV encounters. Mud, water, rocks, and sustained torque loads all contribute to boot wear at a rate that exceeds what recreation-only use would produce. The boot flexes at its fold lines with every inch of rear suspension travel, and the compound that makes up the boot must maintain its elasticity across years of this repetitive flexing. UV radiation from sunlight degrades the rubber even during periods the machine is stored between uses.
When the boot finally fails on the YFM350ER MOTO-4—through a UV-related crack at the fold lines or a physical puncture from debris—CV grease begins to exit through the opening with every rotation and trail contamination enters through the same path. The precision bearing surfaces inside the joint that were running on clean, sealed grease are now running on an increasingly contaminated supply, with the contamination level rising with each ride. Catching the failure before the joint sustains damage is the difference between a boot kit repair and a full axle replacement.
As a 2WD utility ATV, the YFM350ER MOTO-4 drives only the rear wheels. The CV boots are located on the rear axle only—the front wheels steer and roll freely without a driven axle, so this service is rear-focused.
What a Failing Boot Looks and Sounds Like
Finding a failing CV boot on the 1995 Yamaha YFM350ER MOTO-4 before it damages the joint requires knowing the specific evidence. The most visible sign is grease on a surface adjacent to the rear axle—the inner wheel, the rotor, the brake caliper, or the lower frame. A rotating axle distributes CV grease widely once a boot tears, and the deposits accumulate over successive rides. CV grease is visually distinct from road grime and doesn’t blend in with mud or dust. Spotting it on the YFM350ER MOTO-4 near the rear axle warrants an immediate inspection.
Raise the YFM350ER MOTO-4 on jack stands and remove the rear wheel to access the boot. Grip each boot and rotate the axle, looking and feeling for tears, cracks, punctures, and clamp gaps. The fold lines are the most common cracking location, and the zones near both clamp bands are where physical damage tends to concentrate. A boot with visible surface cracking that hasn’t opened fully yet should be replaced in the same session. A clicking or popping sound from the rear end during load tells you the joint behind the boot has already seen some wear.
On the YFM350ER MOTO-4, CV boot service is rear-axle work. The front wheels are not driven and have no CV joints to service on this machine.
Gathering the Right Equipment
Before pulling hardware on the 1995 Yamaha YFM350ER MOTO-4, stage: floor jack and jack stands; correct-size axle nut socket for the YFM350ER MOTO-4; calibrated torque wrench; snap-ring pliers; boot clamp installation tool; and shop rags. The boot kit must include the boot, both clamp bands, and the correct quantity of CV grease. CV grease is a specialized compound designed for the angular velocity and contact pressures inside a CV joint—typically a molybdenum disulfide formulation that maintains a lubricating film under conditions standard grease formulations can’t handle effectively.
Work over a drain pan. Contaminated grease from a torn boot acts as an abrasive in the joint and needs to come out completely. MotoSport.com carries CV boot kits and axle assemblies for the YFM350ER MOTO-4.
Taking the Rear Axle Apart
Get the 1995 Yamaha YFM350ER MOTO-4 on jack stands and remove the rear wheel. Pull the cotter pin, remove the axle nut, and push the axle spline inward to separate from the hub. Use a hub puller if the YFM350ER MOTO-4 has a tight fit. Release the inboard snap ring at the differential with snap-ring pliers and pull the axle free. Set it on a clean surface, cut the clamp bands, and slide the torn boot free. Before installing the new boot, clean the shaft surface and both clamp groove areas on the YFM350ER MOTO-4—grit in the groove prevents proper clamp engagement.
Joint Wear Assessment
Once the boot is off the 1995 Yamaha YFM350ER MOTO-4, wipe old grease away and work the CV joint through its full articulation—compression to extension and full angular rotation. The joint should feel smooth and consistent throughout. Roughness or resistance at a specific angle signals race or ball wear. Hold the shaft and try to move the outer housing side to side and axially beyond its normal articulation. A serviceable joint has firm, controlled movement with no rattle. Any looseness or clunking in the YFM350ER MOTO-4’s joint outside its designed range means the axle assembly needs replacement before a new boot goes on.
Boot Repacking and Clamp Work
Before repacking the 1995 Yamaha YFM350ER MOTO-4, remove all old contaminated grease from the joint’s housing, balls, and races. Thread the replacement boot onto the shaft before reassembling the joint. Work the CV grease from the YFM350ER MOTO-4’s kit in by hand and rotate the housing to distribute it through all the bearing cavities. Use the complete quantity. Position the boot with both ends in the clamp grooves, crimp both clamps to full engagement, and tug each one to confirm it won’t rotate. MotoSport.com carries CV boot kits for this ATV.
Post-Installation Verification
Seat the inboard end in the differential on the 1995 Yamaha YFM350ER MOTO-4 until the snap ring clicks—a pull test should show it locked. Guide the outboard spline into the hub, thread on the axle nut, and torque to the YFM350ER MOTO-4’s specification. Install a new cotter pin or re-stake as required. Reinstall the wheel and torque the lug nuts. Lower the YFM350ER MOTO-4 and move the rear suspension through full travel to verify boot clearance. A short test ride completes the job. MotoSport.com carries CV boot kits and axle assemblies for this ATV.
Related Shopping Categories
Shop CV Joints for a 1995 Yamaha YFM350ER MOTO-4 ATV.
Shop Axles for a 1995 Yamaha YFM350ER MOTO-4 ATV.
Shop Lubricants & Solvents for a 1995 Yamaha YFM350ER MOTO-4 ATV.
Shop Wheel Bearings for a 1995 Yamaha YFM350ER MOTO-4 ATV.
Shop Skid Plates for a 1995 Yamaha YFM350ER MOTO-4 ATV.
Disclaimer: This guide is provided for general informational purposes only and is not intended to replace your ATV's official owner's manual. Always refer to your manufacturer's documentation for model-specific instructions, torque specifications, safety procedures, and maintenance requirements. If you are unsure or inexperienced, consider seeking assistance from a qualified mechanic or technician.
