What Causes Oil Leakage from the Rear Wheels of Large Vehicles?
2 Answers
Oil leakage from the rear wheels of large vehicles is related to the axle head oil seal and the rear axle breather valve. The issue may arise from a damaged wheel hub oil seal or a clogged rear axle breather valve. Potential Hazards: This can lead to ineffective braking, vehicle deviation, and increased gear oil consumption. If the rear axle leaks oil over an extended period without regular checks on the gear oil level and timely refilling, it can cause premature wear of components such as the differential and reduction gears. In severe cases, sudden failure may occur while driving. Additionally, if gear oil from the rear axle flows into the brake drum via the wheel hub, it may wash away some of the bearing grease, leading to insufficient lubrication of the wheel hub bearings. This can result in the erosion and damage of rolling elements or protective rings. Troubleshooting: Upon discovering gear oil leakage from the rear wheels, promptly identify and address the root cause. If the breather valve on the rear axle housing is clogged, replacing it in time can resolve the oil leakage issue. First, verify whether the leaked oil is indeed gear oil before taking appropriate measures. If it is gear oil, check the oil level. If the rear axle gear oil is not excessive, focus on inspecting the rear axle breather valve. Should the breather valve be clogged or damaged, repair or replace it to eliminate the fault.
I often work on heavy-duty vehicles, and the common causes of rear wheel oil leaks are aging or damaged oil seals. The oil seal is the part that seals the lubricating grease, and over time, the rubber can age or wear out, making it prone to oil seepage. Additionally, severe bearing wear can cause grease to leak through the gaps. Cracks in the wheel hub seal or sand and dust intrusion can also lead to oil leaks. A more troublesome issue is when wheel components are deformed in an accident, such as being hit while towing, making it impossible to contain the oil. After an oil leak, insufficient lubrication can cause the bearings to overheat and potentially seize, posing a high risk of brake failure at high speeds. If you notice oil stains, don’t ignore them—get them checked at a repair shop promptly to replace the oil seal or sealing ring. Regular maintenance can help prevent these issues.
