FINAL-DRIVE LUBRICATING OIL COMPOSITION

摘要

A final-drive lubricating oil composition comprising a base oil and, added thereto, (A) 1-10 wt.% of a sulfurized oxymolybdenum organophosphorodithioate represented by general formula (1), (wherein R<1> and R<2>, which may be the same or different from each other, represent each C4-C18 alkyl or alkenyl; and p and q represent each a positive integer provided the sum of them equals 4), (B) 3-15 wt.% of at least one sulfur-base extreme-pressure agent selected from among sulfurized olefins and alkyl sulfides and (C) 0.1-5 wt.% of at least one phosphorus-base extreme-pressure agent selected from among phosphoric esters, phosphorous esters and alkyl-amine salts of phosphoric esters, each based on the whole composition. The composition serves to further improve the transmission efficiency at the differential gear under varied conditions of input torque, input rotational speed and oil temperature as compared with the conventional compositions containing additives based on sulfur and phosphorus compounds, thus leading to fuel consumption improvement.