What are CV joints on a car? What do they do?

Answer 1

Constant Velocity Joints. They transfer torque to the front wheels from the drive train.

Answer 2

In practical terms: CV joints allow a front wheel drive cars to drive and steer through the same (front) wheels by allowing the drive-shafts to bend with the steering whilst driving the wheels (and whilst moving up and down with the suspension).

CV stands for constant velocity because unlike the old universal joint (UJ), it turns at a constant speed relative to the drive-shaft, no matter what angle it is turning through, therefore returning a constant velocity. If the boot protecting these joints split and let in dirt, the joint will wear, it will then 'knock' when being turned with the steering and will have to be replaced before it breaks up.

Answer 3

To test your CV joints, find a large empty car park put your steering on full lock to the left and drive in a doughnut ring then do the same for the right. If you here any knocking or clicking noises coming from the front of your car then you have a problem.

Answer 4

A CV joint is basically a universal coupling

They are on either end of the drive shaft where it connects to the gearbox and wheelhub.

You can't really see the joint because it is hiden behind a rubber "boot"

If the boot cracks or splits, then the grease inside can drop out and the joint can wear away.

They transfer the drive from the gearbox to the wheels. Most wheels are not aligned perfectly with the gearbox, so universal couplings are used to divert the shaft slightly.

More info here.....
http://www.carcare.org/Drivetrain/cv_joints.shtml

Answer 5

You have inner and outer cv joints both do similar jobs .Check the link and all will be revealed.