The Number One Reason for CV Joint Failure

Discover the number one reason for CV joint failure. Review the symptoms associated with constant velocity joint problems and how long you can expect these parts to last. Finally, learn what you can do to get the most time and mileage out of the original equipment parts.

Constant Velocity Joint Operation

CV joints are primarily found on front wheel drive vehicles, but some rear wheel and all-wheel drive cars with independent suspension will use the same type of component on the end of their propeller shafts. On a front wheel drive car the CV joint allows for the trans-axle to continue pushing the vehicle regardless of the steering wheel position. The universal joint also allows power to flow smoothly through varying drive shaft angles and suspension heights as the automobile bounces up and down.

Common Reasons for CV Joint Failure

Constant velocity joints flex through the use of ball bearings and sockets placed between the transmissions driven shaft and the wheel hub attaching to the tire. This allows the movement of the wheel in any direction without disturbing the power flow. They pack the joint in heavy-duty grease to help quiet and facilitate this movement while reducing wear. On high mileage vehicles the rubber boot can deteriorate or develop cracks that allow the grease to escape. Since the shaft and the CV joint spin at high speeds, when the boot breaks, the lubricant is forced out by centrifugal force. Once the joint runs out of lubricant it becomes a metal on metal situation. The joint begins to wear and the damage is not reversible.

Symptoms of Failing CV Joints

The most common complaint when a CV joint begins to fail is a clicking or grinding noise emitting from the area where the joint is located while power is being applied. This is the front left or right wheel on front wheel drive vehicles. Once the noise begins it slowly gets louder over time as the joint begins to self-destruct. Often the noise is best heard at low speeds when turning the steering wheel left or right on hard acceleration. Mechanics will often find an empty parking lot in an attempt to isolate the failing component. From a stop with the steering wheel turned left or right heavy throttle is applied. The joint is under maximum load in these conditions and the unique sound is easier to hear. Once the CV joint begins to develop play between the ball bearings and the socket a vibration can be felt at Highway speeds. A clunk noise when shifting from park to drive is also a common complaint.

How Long CV Joints Last

The way the universal parts move during normal operation combined with the strain of providing constant velocity throughout a range of varying load conditions means the part will not last forever. With that said, manufacturers take into account the amount of work the part must perform during an average lifespan. Since they design the CV joint to be a heavy duty, long-lasting component it’s possible the automobile will go to the junkyard with original equipment installed. Therefore the longevity of the component really relates to the way in which the vehicle is used. Automobiles carrying light loads, operating on smooth highways, will experience low failure rates. Vehicles loaded to the maximum, operating on poor roads or bumpy terrain are more likely to experience CV joint problems. Cars falling into the second category should have the integrity of the CV boot inspected on every automotive service. This is even more critical on cars and light duty trucks with over 100,000 miles.

How to make a CV Joint Last Longer

The weak link in the system is the rubber boot that prevents the lubricant from escaping. Inspect The CV boot for damage as mentioned above. Finding the heavy-duty grease deposited on nearby components is another early warning sign of an approaching problem. The lubricant will often collect on the lower control arm, tie rod ends or on the inside of the dust shield protecting the brake rotors. When problems have been identified and they’re caught before any damage occurs to the CV joint, you can use a part called the speedi boot kit. This is a replacement split rubber boot, lubricant and clamps that install around the constant velocity joint. You can perform the operation without removing the shaft.