Universal Joints

Universal joints compensate for the effects of vehicle loading and axle windup present during acceleration. When operated within designed angle variations, a universal joint will operate effectively. When the designed angle is changed or exceeded, the operational life of the joint will decrease.

On a driveline with a designed deep angle, a Constant Velocity (CV) Joint is used in place of a simple universal joint. A CV joint is composed of 2 universal joints, coupled by a yoke and phased for constant velocity. A ball socket between the 2 universal joints serves as a centering device. See Figure. This causes each of the 2 units to operate through half of the complete angle between drive shaft and differential carrier.

Needle roller bearings are used in universal joints. Needles are held in place on the trunnions by round bearing cups. Bearing cups are held in the yokes either by snap rings or injected plastic retainers, depending on manufacturer.