| 摘要 |
PROBLEM TO BE SOLVED: To obtain a gear oil composition which is excellent in extreme pressure properties, wear resistance, synchronized friction characteristics, oxidation stability, and oil seal adaptability and can commonly lubricate manual speed change gears for automobiles, transfer apparatuses for four-wheel-drive vehicles, and final reduction gears. SOLUTION: This composition is prepared by compounding a base oil having a kinematic viscosity at 100 deg.C of 2-50 mm2/s with (A) 2-10 mass% phosphorus- base and/or sulfur-base extreme pressure agent, (B) 100-500 mass ppm (in terms of boron) boric acid-modified succinimide, (C) 100-1,000 mass ppm (in terms of an alkaline earth metal) alkaline earth metal-base detergent having a base value of 100 mgKOH/g or higher, and (D) 150-1,500 mass ppm (in terms of zinc) zinc primary-alkyldithiophosphate having a 3-30C alkyl group. |
