Abstract: A urea grease of the invention is prepared by applying shear at a shear rate of 102 s?1 or more to a mixture solution of an amine mixture containing an alicyclic monoamine and a chain aliphatic monoamine, and a diisocyanate compound to cause a reaction in the mixture, in which the urea grease has Peak High32-64s of 1.5 or less and Level High32-64s of 10 or less according to an FAG method.

Abstract: A grease composition for constant velocity joints comprises (a) a base oil; (b) a urea thickener; (c) at least one organic molybdenum compound selected from the group consisting of molybdenum dithiocarbamate and molybdenum dithiophosphate; and (d) at least one calcium salt selected from the group consisting of calcium salts of petroleum sulfonates, calcium salts of alkyl aryl sulfonates, calcium salts of salicylate, calcium salts of phenates, calcium salts of oxidized waxes, overbasic calcium salts of petroleum sulfonates, overbasic calcium salts of alkyl aryl sulfonates, overbasic calcium salts of salicylate, overbasic calcium salts of phenates, and overbasic calcium salts of oxidized waxes. The grease composition exhibits good performance for reducing vibration and effectively lubricates the constant velocity joints to effectively reduce frictional wear and to eliminate vibration.

Abstract: A grease composition for constant velocity joints comprises (a) a base oil; (b) a lithium-containing thickener selected from the group consisting of lithium soap and lithium complex soap; (c) an organic molybdenum compound selected from the group consisting of molybdenum dithiophosphates and molybdenum dithiocarbamates; (d) a zinc dithiophosphate; (e) a sulfur-phosphorus extreme pressure agent free of any metal; and (f) a calcium salt selected from the group consisting of calcium salts of oxidized waxes, calcium salts of petroleum sulfonates and calcium salts of alkyl aromatic sulfonates. The grease composition for constant velocity joints exhibits a substantially improved effect of reducing friction coefficient and a substantially improved effect of reducing the axial force proportional to the third order component of rotation.

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.