25172118
U-Joint
Mack

The U-joint (universal joint) provides a flexible connection in the driveline, accommodating changes in angle between the transmission and axle while transmitting torque. This heavy-duty joint uses a cross and four bearing surfaces with robust seals to resist dirt and moisture. Proper lubrication is essential to minimize wear, vibration, and potential binding during acceleration or deceleration on uneven roads. A well-maintained U-joint contributes to smooth drivetrain operation, reduces the risk of driveline failure, and extends overall system life. When replacing, ensure correct cross size, yoke pattern, and lubrication provisions match the original specification. Source One Parts Center.