What Causes the Noise When Shifting Gears in an Automatic Transmission?
2 Answers
Automatic transmission shifting noise can be caused by: 1. Lack of lubricant in the release bearing; 2. No gap between the release bearing and the inner end of the release lever; 3. Dirt between the release bearing sleeve and the guide tube, or fatigue, breakage, or detachment of the release bearing return spring and pedal return spring; 4. Loose fit between the driven plate spline hole and its spline shaft; 5. Fatigue or breakage of the driven plate damping spring; 6. Loose rivets on the driven plate friction disc. An automatic transmission means the driver does not need to manually shift gears; the vehicle automatically selects the appropriate gear based on driving speed and traffic conditions, making driving more convenient.
I've been driving automatic transmission cars for over twenty years and have encountered gear shifting noises several times. The most common causes are insufficient or dirty transmission fluid, leading to poor lubrication and gear friction sounds. If the fluid level is low, simply top it up with the appropriate fluid; if it's dirty, replacing it isn't expensive. Another reason could be loose gear shift levers or related components, which is common in older cars—they tend to rattle when vibrating. Sometimes, the noise is louder when the car is first started in cold weather but disappears once warmed up, which is normal. However, persistent noises should be taken seriously, as they might indicate internal transmission wear, such as worn clutch plates or damaged bearings. Delaying repairs could lead to costly overhauls. To prolong transmission life, avoid aggressive acceleration during gear shifts and adhere to regular maintenance. Remember, safe driving is paramount—if the noise becomes severe, seek a professional inspection promptly.
