Ensuring you are Ready for the Road Ahead , the Spicer 1710 Series Universal Joint allows drive shafts to move up and down with the suspension while your semi truck's shaft is moving. With compact fit engineering, this heavy duty replacement u-joint ensures power can be transmitted when the driveshaft is not in a straight line between the transmission and drive wheels. Gain superior life and decreased maintenance time/costs of this universal joint with 180° positioned zerks positioned on both sides for consistent lubrication without rotation of driveshaft. FleetPride is your First Click in Heavy Duty .