As one of the three major components of a vehicle, the transmission operates under high-temperature, high-pressure, and heavy-load conditions for long periods of time. Within the entire transmission system, there is a crucial component — the transmission oil pan.

   Many car owners believe that the oil pan is simply a component used to store transmission fluid, and that it can be ignored as long as there is no oil leakage. In fact, as the vehicle ages and accumulates more mileage, the oil pan, along with its internal filter element and sealing components, will gradually deteriorate. This can not only affect the normal operation of the transmission but may also accelerate wear on internal components.

   If oil stains are found on the ground after the vehicle has been parked, oil residue is noticed around the edges of the oil pan during inspection, or the transmission fluid level continues to drop, it is likely that the leakage is caused by aged sealing rings, a cracked oil pan, or deformation of the oil pan.

   The transmission oil pan operates under high-temperature and high-pressure conditions for extended periods. If the vehicle experiences impacts to the undercarriage or is repeatedly affected by thermal expansion and contraction, the oil pan may become deformed or even crack. Once the housing is deformed or damaged, it can not only compromise the sealing performance but may also lead to continuous transmission fluid leakage.

   The transmission oil pan helps dissipate heat from the transmission fluid and maintain a stable operating temperature. When a large amount of sludge and dirt accumulates on the surface of the oil pan, or when aging and deformation affect its heat dissipation performance, the transmission fluid temperature can easily rise. Prolonged exposure to high temperatures not only accelerates transmission fluid deterioration but also reduces lubrication performance, increases wear on internal components, and shortens the service life of the transmission.

   The oil pan is sealed to the transmission housing by a gasket. As the vehicle ages and accumulates more mileage, the sealing gasket may become aged, hardened, or lose its elasticity, resulting in reduced sealing performance. In mild cases, oil seepage may appear around the edge of the oil pan; in more severe cases, continuous leakage can occur, leading to insufficient transmission fluid levels.

   随着行驶里程增加，变速箱油会逐渐氧化、变质，黏度下降，润滑和散热性能减弱，同时还会混入金属碎屑、摩擦颗粒等杂质。长期使用老化变质的变速箱油，不仅会加剧内部零部件磨损，还可能出现换挡顿挫、换挡延迟、异响等现象。

   As mileage increases, transmission fluid gradually oxidizes and deteriorates, causing its viscosity to decrease and reducing its lubrication and heat dissipation performance. At the same time, it becomes contaminated with metal shavings, friction particles, and other impurities. Continuing to use degraded transmission fluid can accelerate wear of internal transmission components and may lead to issues such as harsh shifting, delayed gear engagement, and abnormal transmission noise.

变速箱油底壳保养指南

Transmission oil pan maintenance guide

Different vehicle models are equipped with different transmission types, resulting in variations in oil pan structure, interface locations, and filter designs. When replacing the oil pan, it is essential to choose one that precisely matches the original vehicle specifications to ensure secure installation and prevent oil leakage issues.

When replacing the oil pan, some or all of the transmission fluid usually needs to be drained. It is recommended to replace the transmission fluid that meets the required specifications at the same time, depending on the actual condition of the vehicle.

Avoid prolonged aggressive driving, frequent rapid acceleration, sudden braking, and extended high-load operation to reduce stress on the transmission.

   Many transmission failures do not occur suddenly but are the result of long-term neglect of routine maintenance and regular inspections. Timely inspection and replacement can not only improve shifting smoothness but also reduce internal wear, helping to extend the service life of the transmission.