Tribological investigation of grease used in automotive constant-velocity joints

High performance greases with separate additive formulations for low friction and wear have been developed specifically for constant-velocity (CV) joints. CV joint grease performance was studied utilizing a versatile pin-on-disk tribometer. Tests were conducted under dry and submerged grease lubricated conditions using two CV joint greases containing different additives. Grease B with solid EP additives showed better friction performance at normal contact pressures below 300 MPa, at which point grease A became superior due to its organo-molybdenum pressure sensitive additives. Grease B achieved better wear performance over grease A, but this trend was not readily apparent with negligible differences in wear depths of the disks. Balancing combinations of low friction and anti-wear additives were necessary in the development of CV joint greases to improve CV joint performance and durability. This is an abstract of a paper presented at the 2006 STLE Annual Meeting Conference Proceedings (TELUS Convention Centre Calgary, Alberta, Canada 5/7-11/2006).