CV (constant velocity) Joints

CV Joints (Constant Velocity Joints)

If you are considering buying a used vehicle equipped with CV joints, be sure to check for leaking or damaged CV boots.

CV joints are used on many types of vehicles especially FWD, 4X4 and AWD (all-wheel drive). CV joints attached to the drive axles allow power from the final drive assembly to be transmitted to the tire and wheel assembly thus powering the vehicle down the road. The CV joint allows the axle to flex or change angles to allow you to steer around a corner while transferring torque to the road. Also, these angles change as the vehicle suspension increases or decreases its ride height as road surfaces and load changes.

The longevity of the CV joint depends on its lubrication which is a special designed lubricant that is sealed inside a boot. The boot looks similar to a ribbed billows surrounding the inner and outer joints or the drive axles. When the boots leak joint damage will occur quickly. Remanufactured axle assemblies or boot kits are available as a repair. Either repair choice is not cheap. (Call or search online for prices/estimates).

If boots are leaking, damage to the joint may cause a rapid popping noise, especially while turning a sharp corner or accelerating. If popping occurs, forget the boot kit ‘fix’ and go with the axle assemblies.

4 X 4 &/or AWD

4-wheel drive (4wd)
The 4wd gives the driver the option of driving in 4wd or two-wheel drive (2wd). These vehicles can be basically a front wheel drive (fwd) or rear wheel drive (rwd). Some also, in addition to the fwd/2wd option, have a high and low range option.

All-wheel drive (awd)
The awd vehicles do not have an option of 4wd or 2wd. They are in 4wd at all times and transfer power to the wheels with the most traction through a viscous clutch.

Most manufacturers offer both types in some of their product lines.