C.V. joints, also named as Constant-velocity joints, play an important part in car’s drive system,they make the C.V. axle to transfer the engine’s power to the drive wheels at a constant speed, because the C.V. joint is an assembly of bearings and cages that allows for axle rotation and power transmission at a number of different angles.CV joints consist of a cage, balls, and inner raceway encased in a housing covered by a rubber boot,which is filled with lubricating grease.The C.V. Joints include inner C.V. Joint and the outer C.V. Joint. Inner CV joints connect the drive shafts to the transmission, while the outer CV joints connect the drive shafts to the wheels.CV joints are on both ends of the C.V. Axle,so they are part of C.V. Axle.