The U-joint is secured to the yoke in one of two ways. Dana and Cleveland shafts use a conventional snapring to hold each bearing cup in the yoke. The snapring fits into a groove located in each yoke end just on top of each bearing cup. The Saginaw design shaft secures its U-joints in another way. Nylon material is injected through a small hole in the yoke and flows along a circular groove between the U-joint and the yoke, creating a synthetic snapring. Disassembly of the Saginaw U-joint requires the joint to be pressed from the yoke. This results in damage to the bearing cups and destruction of the nylon rings.
Replacement kits include new bearing cups and conventional snaprings to replace the original nylon rings. These replacement rings must go inboard of the yoke in contrast to outboard mounting of the Dana and Cleveland designs. Previous service to the Saginaw U-joints can be recognized by the presence of snaprings inboard of the yoke.
Bad U-joints, requiring replacement, will produce a clunking sound when the car is put into gear. This is due to worn needle bearings or a scored trunnion end possibly caused by improper lubrication during assembly. Firebird U-joints require no periodic maintenance and therefore have no lubrication fittings.