What if the BMW gearbox fails occasionally?

The failure of automatic gearbox is often not the damage of internal valve body, but the stubborn dirt and impurities inside the valve body, especially the accumulation of dirt and impurities inside the valve body to form a blockage, which leads to the inability to effectively adjust the oil pressure, leading to frustration, impact and slippage. At the same time, the problem of high gearbox temperature can not be ignored. According to the data of automatic transmission maintenance association, "more than 90% of all faulty automatic transmissions are caused by overheating."

High temperature will destroy the quality and friction characteristics of automatic transmission oil, increase friction and wear, and the noise of transmission will follow. At the same time, sludge (impurities or dirt) will also be produced inside the transmission (such as the valve body), which will lead to the frustration and impact of the transmission. If the temperature exceeds 120℃, the rubber sealing material will start to harden, which will eventually lead to leakage and reduce the hydraulic pressure. If the temperature is higher, the gearbox will start to slip, which will increase the temperature. (Audi and other high-end models will call the police and enter the gearbox protection mode. If it is not solved in time, the gearbox will be scrapped.

Therefore, only by removing stubborn dirt and impurities in the gearbox and effectively controlling the working temperature of the gearbox can the gearbox problem be completely solved and prevented from happening again. This is also the key to achieve "no disassembly and no repair to solve the gearbox fault", and the specific content can be learned in detail by Baidu.