What Causes the Clunking Sound When Shifting to Reverse in an Automatic Car?

[ElliottAnn]

Automatic car shifting to reverse gear causes a clunking sound: Engaging reverse gear involves the activation of a reverse lock mechanism, which typically produces a very slight clunking sound. If the sound is excessively loud, it is necessary to inspect this reverse lock. The full name of the reverse gear is the reverse driving gear, which is one of the standard gears in a car. It is labeled as "R" on the gear console and is designed to enable the vehicle to move backward, serving as a special type of driving gear. After shifting to reverse, the vehicle's direction of movement will be opposite to that of the forward gear, allowing the car to reverse. When the driver moves the gear lever to the reverse position, the direction of the engine's power input remains unchanged, while the internal reverse output gear of the transmission engages with the output shaft, driving the output shaft to rotate in the opposite direction. This ultimately causes the wheels to rotate in reverse, enabling the car to move backward.