What Causes the Sudden Jerking When Starting an Automatic Transmission Car?

[MacBethany]

Experiencing jerking when releasing the brake during start-up can be attributed to several factors. For instance, internal transmission issues, such as excessive wear leading to gaps, can cause looseness during start-up, resulting in a jerking sensation. The best solution to such problems is to replace the transmission fluid and perform a comprehensive transmission maintenance. Additionally, avoid aggressive driving in daily use to prevent accelerated transmission wear. This phenomenon is quite common in high-performance vehicles with significant horsepower, especially those equipped with AT transmissions. During rapid acceleration, the engine speed increases extremely quickly, causing a noticeable impact when shifting from 1st to 2nd gear. Particularly when the throttle is pressed hard, raising the engine speed to five or six thousand RPM or even higher, the transmission must abruptly reduce the speed from five or six thousand RPM to two or three thousand RPM to ensure smooth engine operation. This sudden reduction in speed generates the impact, which is the so-called jerking sensation. However, during rapid acceleration, the jerking sensation in lower gears becomes significantly more pronounced.