Is Low-Speed Jerking in a Car a Sign of Transmission Problems?
1 Answers
Low-speed jerking in a car is not necessarily a sign of transmission problems; it simply indicates that the input speed (engine RPM) and output speed (transmission speed determined by vehicle speed) of the clutch are not synchronized. First, there is a speed difference between the engine and transmission during gear shifts. Second, the engagement control of the "clutch" is not precise enough, leading to jerking sensations at low speeds. The way to eliminate jerking is to ensure that the input and output speeds of the clutch are perfectly matched during every gear shift. Experienced drivers, through practice, learn the approximate speed differences between gears and the rate at which the engine RPM drops (which depends on engine design—generally, high-performance, high-revving engines drop faster, while engines with higher exhaust resistance drop slower). By timing the gear shift based on the engine RPM drop, they can find the "rhythm" for smooth shifting. The specific method involves releasing the throttle, pressing the clutch, shifting gears while the engine RPM starts to drop, and engaging the clutch once the RPM matches the next gear's target speed. Of course, not every shift will be perfectly timed. Experienced drivers typically release the clutch 70% first, allowing it to partially engage and gently synchronize the engine and transmission speeds, thereby reducing jerking.
