Why does the automatic transmission make a clunk sound when shifting into reverse?

[DawsonLee]

Automatic transmission making a clunk sound when shifting into reverse indicates a vehicle malfunction. Here are the possible causes: 1. Electronic linkage: The clutch pedal isn't fully depressed during gear shifting, causing gear damage. 2. Idle gear shifting: In automatic transmission vehicles, the engine RPM is very high during the first few seconds after startup. If you shift from neutral to reverse before the engine speed stabilizes, it will cause strong impact vibrations to the transmission. 3. Reverse gear lacks synchronizer: The synchronizer is an internal transmission device that ensures smooth gear engagement during gear changes. Some vehicles don't have synchronizers, making gear shifting more difficult.