| abstract |
A grease composition for use in a slidable type constant velocity universal joint comprises a lubricant base oil, (A) 2 to 25 wt.% of a thickener containing a mixture of (i) 25 to 93 mol% of a diurea compound represented by the formula (i) of R2NHCONHR1NHCONHR3 (ii) 4 to 30 mol% of a urea-urethane compound represented by the formula (ii) of R5NHCONHR4NHCOOR6 and (iii) 3 to 45 mol% of a diurethane compound represented by the formula (iii) of R8OCONHR7NHCOOR9 wherein R1, R4 and R7 stand for a divalent aromatic hydrocarbon group, R2, R3 and R5 stand for a cyclohexyl group or a cyclohexyl derivative group, and R6, R8 and R9 stand for an alkyl group or an alkenyl group; (B) 0.1 to 10 wt.% of an alkali metal borate hydrate; (C) 0.1 to 10 wt.% of a molybdenum compound selected from the group consisting of molybdenum dithiophosphate, molybdenum dithiocarbamate, molybdenum disulfide and mixtures thereof; and (D) 0.1 to 10 wt.% of a sulfur-phosphorus base extreme pressure additive selected from the group consisting of sulfides of fats and oils, polysulfides, phosphates, phosphites, thiophosphates, dithiozinc phosphates and mixtures thereof. |