Why Does the Transmission Shift with a Jerk?
2 Answers
For automatic transmissions, the reason for jerky shifting is due to the generation of rotational speed difference and the imprecise synchronization process after gear shifting. AT Transmission: Traditional AT transmissions rely on the torque converter, a flexible transmission component. The term 'flexible' is relative to 'rigid'; clutch transmission is considered rigid transmission. Therefore, AT transmissions are generally easy to achieve smoothness, thanks to the torque converter. Since it's hydraulic transmission, it naturally loses some energy efficiency, so fuel consumption becomes the weak point of AT transmissions. Dual-Clutch Transmission: Volkswagen's DSG transmission shifts quickly and smoothly. Smooth shifting requires the absorption of rotational speed difference, which is a physical law unrelated to the shifting mechanism of the transmission.
Transmission shift hesitation is quite annoying. I experienced it in my own car last month—every time it shifted, there was a jerk, making the car feel unstable and rough. The main causes include aging or insufficient transmission fluid; dirty or low fluid levels can affect lubrication, leading to unsteady clutch and gear movements. Additionally, mechanical parts like excessively worn clutch plates or faulty solenoid valves can cause unstable control, resulting in hesitation. There’s also the issue of signal errors in the computer control module—for example, inaccurate sensor readings can throw off the shift points. In my case, I found the fluid was nearly depleted, and after replacing it with fresh fluid, the problem improved significantly. If you feel this while driving, it’s best to check the fluid and sensors. Over time, it can impact fuel efficiency and driving comfort, and in severe cases, damage the transmission. Taking it to a professional shop is the safest bet.
