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

[JustinDella]

Experiencing a jerking sensation when releasing the brake during startup can be attributed to various factors. For instance, internal transmission issues, such as excessive wear leading to gaps, can cause play during startup, resulting in a jerking sensation. The best solution to such problems is to replace the transmission fluid and perform a comprehensive transmission maintenance. Additionally, it's advisable to avoid aggressive driving in daily use to prevent accelerated transmission wear. This phenomenon is quite common in high-performance vehicles with substantial 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 accelerator is pressed hard, raising the engine speed to five or six thousand RPM or even higher, the transmission must downshift to reduce the speed from five or six thousand RPM to two or three thousand RPM to stabilize the engine speed. This process generates an impact, which is the so-called jerking sensation. During rapid acceleration, the jerking sensation in lower gears can become particularly intense.