Lack of lubrication is the first cause of early failure for universal joints, according to Thomas Koedam, with Dana Corp. He told a group gathered at the Technical Conference of the Association of Equipment Management Professionals (AEMP) they should grease U-joints used in on/off-highway work every 5,000 to 8,000 hours. He stressed the importance of purging recommended grease from all four bearing seals of each U-joint.
"If any of the seals fail to purge, move the driveshaft from side to side while applying grease-gun pressure to the fitting," Koedam says. "As a last resort, back off the bearing cap bolts and pump grease. You must get grease into all four seals."
Bolts in Spicer's full-round yokes with lock strap can be reused. But you must replace the bolts on Spicer's quick-disconnect half-round yokes, or full-round yokes with serrated bolts. Remember to torque the bolts to the manufacturer's specifications.