Grease composition for constant-velocity joint and constant-velocity joint filled therewith

A grease composition for a constant-velocity joint, comprising:

• (a) a base oil having a kinematic viscosity of 16.0 mm2/s or more at 100° C. and a viscosity index of 90 or more;
• (b) a diurea-based thickener represented by the following formula (1)
• wherein R1 and R1′ are each independently an octyl group, a dodecyl group, a hexadecyl group, an octadecyl group, or a cyclohexyl group;
• (c) 0.2 to 2.0% by mass of a zinc dialkyldithiophosphate;
• (d) 0.5 to 2.0% by mass of a non-oil-soluble molybdenum dialkyl dithiocarbamate;
• (e) 0.5 to 3.0% by mass of an oil-soluble molybdenum dialkyl dithiocarbamate;
• (f) 1.0 to 4.0% by mass of a zinc dialkyldithiocarbamate;
• and
• (g) 0.1 to 1.5% by mass of a benzothiazole-thione or a derivative thereof, wherein a mass ratio between the component (f) and the component (g) is (f):(g)=8:1 to 3:1