Proper lubrication of any moving part in a driveline is essential to keep it in proper working order and to obtain an acceptable service life.

All universal joints, slip yoke and stub shaft assemblies, as well as centering kits in CV heads should be greased regularly.

Universal joints – Secure grease gun on grease fitting and pump in the grease until all four bearings are lubricated to check for this, make sure that all four seals have purged out air and old grease. Grease until fresh grease appears at the base of all four seals. If a seal does not purge properly, move the driveline to free up the end-to-end clearance of the bearing cup. On bearing plate style U-joints, it may be necessary to loosen the bolts two or three turns to allow grease to flow. If the joint still does not grease properly, disassemble the kit to determine the source of the problem.
Slip Yoke and Stub Shaft Assemblies – Before putting the slip yoke onto the stub shaft, coat both parts uniformly with a layer of grease. After assembly, but before installation into the vehicle, fully collapse the driveline and apply the grease to the grease fitting until it comes out of the vent hole in the welch plug. Cover the hole and continue greasing until grease appears in the seal.    At re-lubrication it may be impossible to fully collapse the driveline. Follow the same general greasing procedure but be careful not to overfill. Overfilling may cause the welch plug to pop out during operations.
Center Kits *Worn centering kits will squeak, do not ignore this. Centering kits can wear fast and cause severe damage. A special needle nose grease gun adapter is needed to grease the flush type fitting on centering kits. Apply grease until fresh grease appears at purge hole or at ball seal.

The frequency of lubrication is determined by the type of service the driveline is subject to. A list of recommended re-lube cycles for various service conditions is shown below.

Service Conditions

Re-Lube Period

Approximate Miles

City Every 2 Months 6,500
Highway Every Month 12,000
Off Highway Every 3 Months 6,500
Line Haul Every 1-2 Months 20,000 – 30,000
Off Highway 4×4 Every Month 2,500