Abstract: A grease composition for use in ball type constant velocity joints, which comprises the following components a base oil; a diurea thickener of the formula: R1—NH—CO—NH—C6H4-p-CH2—C6H4-p-NH—CO—NHR2 wherein R1 and R2 are alkyl groups having 8 carbon atoms, molybdenum disulfide; molybdenum dithiocarbamate of the formula: (R3R4N—CS—S)2—Mo2OmSn wherein R3 and R4 independently represent an alkyl group having 1 to 24 carbon atoms, m is 0 to 3, n is 4 to 1 and m+n=4, calcium salts or overbasic calcium salts of petroleum sulfonates, sulfur-phosphorus extreme pressure agent, and castor oil. The grease composition exhibits excellent wear-resistance and pitting-inhibitory effect.

Abstract: A grease composition for constant velocity joints which consists essentially of: (a) a base oil; (b) an urea thickener; (c) molybdenum disulfide; and (d) a metal salt or an overbasic metal salt selected from the group consisting of metal salts or overbasic metal salts of oxidized waxes, petroleum sulfonates, alkyl aryl sulfonates, salicylate, and phenates. In addition to (a) to (d), it may further contain, (e) an extreme pressure agent selected from the group consisting of a metal-free sulfur-phosphorus extreme pressure agent and molybdenum dithiophosphate, or (f) molybdenum dithiocarbamate. The grease composition exhibits excellent wear-resistance and pitting-inhibitory effect.