If you experience vibrations while accelerating at highway speeds you might have worn CV Axles. This happens more commonly on front wheel drive cars. Vehicles with independent suspensions use constant velocity joints to allow the axle to articulate as the car turns or the suspension moves independently. They spin at the same speed as your engine so if you are cruising at 2,100 RPM so are your CV Axles. Like every moving part of your suspension they can also wear. As they wear they will cause a clicking noise when you turn and a vibration when you accelerate.

CV axles have a few failure points as they age. The most common failure comes from the external rubber boot tearing and leaking. The grease inside the joint then gets flung out and the joint gets dry. Without lubrication the metal on metal contact between the joint and the CV housing causes the CV axle to have play and fail. The axle can also develop rust and snap during hard acceleration. Finally the CV joint can just fail due to wear and tear.

If a tear is found on a CV boot quickly enough the boot can simply be replaced and the joint re-packed with grease assuming there is no play in the joint. The joint can also be replaced as long as the inner CV housing wasn’t damaged where the new joint has play. In most other situations it is better to replace the whole CV Axle as the labor to change the boot and joint is equal to or greater than the cost of replacing the whole assembly.

The play in the CV Axle joint causes the vibrations as the joint rotates thousands of times a minute. The rotation causes the joint to move inside the housing and bounce around accelerating the failure and causes the vibration you feel as your drive on the highway. The symptoms of a worn CV joint in an axle are a clicking sound when you turn your steering wheel most noticeable when driving around at low speed in a parking lot. You will also feel a vibration particularly while accelerating on the highway.

The vibrations at highway speeds can cause the seals where your axle connects to your differential seals to leak and lose lubricating fluid, which will lead to differential or transmission damage depending on your car being front wheel drive, rear wheel drive, or all wheel drive. The play inside the joint can cause the housing or axle to break, which will make the car un-driveable requiring you to need a tow. As mechanical problems tend to cascade it is always best to get your car repaired sooner rather than waiting for something to break and leave your car un-driveable. If you have an questions feel free to contact us for all your auto repair and maintenance needs.