This bevel gear oil seal assembly, also known as pinion oil seal, is a critical sealing component installed at the input end of FAW heavy truck rear axle gearbox. It seals the lubricating oil inside the rear axle reducer and prevents oil leakage, while blocking dust, mud and water from entering the gear meshing area. Constructed from high-temperature resistant fluororubber composite material with rigid metal skeleton, it maintains stable sealing performance under high temperature, high pressure and continuous vibration during long-haul heavy transport. Precision lip design minimizes friction loss and prolong service life. Every oil seal assembly undergoes sealing inspection and aging test before delivery. It solves rear axle oil leakage, gear oil contamination and premature gear wear problems, serving as an essential replacement spare part for heavy truck rear axle maintenance.