What Causes the Abnormal Noise When Shifting from 2nd to 3rd Gear in a Volkswagen Passat?
1 Answers
When abnormal noises occur in an automatic transmission, it is often not due to damage to the internal valve body but rather the presence of stubborn dirt and impurities inside. Especially when these contaminants accumulate within the valve body, they can form blockages, preventing effective regulation of oil pressure and leading to issues such as jerking, impact, and slippage. Additionally, the problem of high transmission temperatures should not be overlooked. Factors involved: High temperatures can degrade the quality and frictional properties of automatic transmission fluid, increasing friction and wear, which in turn leads to transmission noise. At the same time, sludge (impurities or dirt) can form inside the transmission (e.g., in the valve body), causing jerking and impact. If the temperature exceeds 120 degrees Celsius, rubber sealing materials will begin to harden, eventually leading to leaks and reduced hydraulic pressure. At even higher temperatures, the transmission may start to slip, and this slippage can further raise the temperature. If not addressed promptly, the transmission may fail completely. Precautions: To thoroughly resolve transmission issues and prevent their recurrence, it is essential to remove stubborn dirt and impurities from the transmission and effectively control its operating temperature.
