What Causes the Noise When Shifting Gears in a New Automatic Car?
2 Answers
New automatic cars making noise when shifting gears may be caused by the following reasons: 1. Operational issues: If the clutch is not fully disengaged during gear shifting, it can cause gear noise and even gear grinding. 2. Contaminated transmission fluid: If the transmission fluid contains large impurities, such as metal shavings from long-term wear, these particles can get caught between the gears during rotation, leading to gear grinding. 3. Synchronizer problems: Manual transmissions have a crucial component called the "synchronizer." Its function is to match the speed of the input gear (which is usually faster) with the gear being engaged during shifting. Without a synchronizer, forcing a slow-moving gear into a high-speed one will inevitably cause gear grinding.
New cars with automatic transmissions may produce noise when shifting gears due to several common reasons. During the break-in period, internal transmission components such as gears or bearings need to adapt, resulting in temporary friction sounds. It could also be a hydraulic system issue, where unstable oil pressure causes rough gear shifts. Insufficient or contaminated transmission fluid can also trigger noise. I once encountered a similar situation where a new car made a clicking sound when shifting, and later inspection revealed low fluid levels. It is recommended to have a comprehensive inspection during the first maintenance service to prevent minor issues from escalating. In daily driving, gently applying the brakes before shifting can reduce the risk of abnormal noises.
