U-Joint (Universal Joint)


There are several methods of holding the U-joints to the yokes. Universal joints are usually pressed fit into the yokes on the driveshaft. Snap rings fit into grooves in the yoke to keep the joint centered and retained. The most popular mounting found on cars is one where U-bolts hold the U-joint in place between tabs in the rear flange. On the rear flange, there must be a feature that aligns the joint on center. Alignment is done by either tabs on the outsides or snap rings on the ends. Instead of snap rings, some original equipment joints are held in place with injected molded plastic. If the driveshaft is not installed exactly on center, serious vibration will result.

Several methods of holding universal joints to yokes.

To replace the U-joints:

  • Remove the driveshaft.
  • Clamp the slip yoke in a vise and support the outer end of the drive shaft.
  • Remove the lock rings on the tops of the bearing cups. Make index marks in the yoke so that the joint can be assembled with the correct phasing.
  • Select a socket that has an inside diameter large enough for the bearing cup to fit into; usually a 1-1/4 inch socket works.
  • Select a second socket that can slide into the shaft's bearing cup bore-usually a 9/16-inch socket.
  • Place the large socket against one vise jaw. Position the drive shaft yoke so that the socket is around a bearing cup.
  • Position the other socket to the center of the bearing cup opposite to the one in line with the large socket.
  • Carefully tighten the vise to press the bearing cup out of the yoke and into the large socket.
  • Separate the joint by turning the shaft over in the vise and driving the spider and remaining bearing cup down through the yoke with a brass drift and hammer.
Art courtesy of Delmar - Thomson Learning.
  • Use a drift and hammer to drive the joint out of the other yokes.