| 摘要 |
PROBLEM TO BE SOLVED: To obtain the subject composition that has excellent oxidation stability, pitching resistance, extreme-pressure properties, the friction properties between the synchronizer ring and the gear cone and has largely increased shear stability on the multigrading by formulating specific components thereto. SOLUTION: This gear oil composition is prepared by formulating (A) a zinc primary dithiophosphate bearing an alkyl group of 8 or more carbon atoms, (B) an alkaline earth metal type detergent dispersant with a base value of >=200 mg KOH/g, (C) a polybutenyl group-containing bis(alkenyl succinimide) or its derivative, (D) an amine salt of phosphoric ester, (E) a sulfur compound selected from hydrocarbon sulfides and sulfide resins, (F) an ethylene-α-olefin copolymer with an average molecular weight of 2,000-12, 000 and (G) a poly(methacrylate) polymer with an average molecular weight of 15,000-50,000. |
