Is it normal for an AT transmission to jerk when cold?
1 Answers
AT transmission jerking when cold is not normal. The phenomenon where gear shifts jerk when the car is cold but become smooth when warmed up is often due to leakage in the clutch sealing components, which expand when hot and contract when cold, causing the jerking to disappear as the transmission warms up. Another possible cause is insufficient transmission fluid; if the fluid level is below the normal range, adding an adequate amount of transmission fluid can resolve this issue. Jerking refers to the slight, brief shaking that occurs during gear shifts in the transmission. Possible reasons for jerking include defective control programs, poor self-learning capability, and lack of maintenance. Poor self-learning capability: The AT transmission control program has a core function called self-learning, which automatically corrects hardware deviations and subsequent wear. For example, if the transmission control unit detects that a gear shift takes too long, it may increase clutch engagement pressure during the next shift to speed up the process. This requires advanced software data and algorithms, which most automakers rely on a few suppliers to provide. Variations in tuning and matching can lead to jerking. Lack of maintenance: The transmission contains complex mechanical components that inevitably wear during operation. Even with a transmission filter, some impurities may mix into the transmission fluid, leading to jerking.