What Causes Jerking When Starting in D Gear with an Automatic Transmission?
1 Answers
Jerking when starting in D gear with an automatic transmission is caused by persistent dirt and contaminants inside the transmission, particularly when these accumulate in the valve body, forming blockages that prevent effective regulation of oil pressure, leading to jerking, impact, and slipping issues. More details are as follows: Main causes of jerking: High temperatures can degrade the quality and frictional properties of automatic transmission fluid, increasing friction and wear, which leads to transmission noise. Simultaneously, sludge (contaminants or dirt) can form inside the transmission (e.g., in the valve body), causing jerking and impact. If the temperature exceeds 120°C, rubber sealing materials begin to harden, eventually leading to leaks and reduced hydraulic pressure. Solution: If the temperature rises further, the transmission may start to slip, and slipping in turn raises the temperature even higher. (High-end models like Audi may trigger warnings and enter transmission protection mode.) If not addressed promptly, the transmission may fail. Therefore, thoroughly removing stubborn dirt and contaminants from the transmission and effectively controlling its operating temperature are essential to completely resolve transmission issues and prevent recurrence.