| 摘要 |
PROBLEM TO BE SOLVED: To provide a gear oil compsn. which is suitable for manual transmissions of automobiles, can realize common use in a final reduction gear, has excellent extreme pressure properties and heat resistance, and can improve friction properties between a synchronizer ring and a gear cone, particularly durability of the coefficient of friction, regardless of the material of the synchronizer ring (a brass material or a resin material). SOLUTION: This gear oil compsn. comprises: a base oil (component A) composed of one oil or a mixture of two oils selected from mineral oils or synthetic oils having a viscosity of 2 to 50 mm<2> /sec at 100 deg.C, a pour point of -15 deg.C or below, and a sulfur content of not more than 0.7 mass %; and, added to the base oil, 0.05 to 8 mass % at least one sulfur compd. (component B) selected from hydrocarbon sulfide, terpene sulfide, and sulfurized fat and oil, 0.1 to 6 mass % at least one phosphorus compd. (component C) selected from acid phosphoric esters of alcohols having an 8C or higher alkyl group or alkylamine salts thereof, and 0.1 to 7 mass % boron compd. deriv. of an alkenylsuccinimide (component D). |
