What causes a clunking sound when reversing?
3 Answers
Here are the reasons for a clunking noise when reversing: 1. Damaged car tires can cause abnormal noises when reversing or moving forward. Solution: Repair or replace the tires. 2. Faulty car shock absorbers can also produce abnormal noises when turning or driving on bumpy roads. In this case, the shock absorbers need to be replaced at a repair shop or 4S store. 3. Transmission issues, such as damaged reverse gears, can cause friction-related noises. This requires opening the transmission to inspect and replace the gears. 4. Brake pad problems, including improper installation, severe wear, or foreign objects stuck between the pads and calipers. Specific solutions involve removing the car tires to inspect the brake pads and then performing repairs, with replacement being necessary in some cases.
Yesterday, my neighbor also heard this clunking sound while reversing, and later found out it was caused by rusted brake discs and pads sticking together. This is particularly common for vehicles parked outdoors after rain, especially if left unused for a week—you'll hear a 'clunk' the moment you start moving. If parked on a slope and reversing, you might even hear the metallic creaking from the suspension system under stress. Once, after my car sat in the garage for too long, it made noise when reversing, and I discovered some loose and deformed components inside the wheels—had to rush to the repair shop to tighten them. Sometimes, it's just tools in the trunk not being secured properly, rattling and colliding while driving. Best to check the trunk for loose items after turning off the engine.
This sound is most likely coming from the chassis system. I once experienced a clunking noise when reversing in a manual transmission car, and it turned out to be a worn CV joint. For most automatic transmission vehicles nowadays, it could be due to aging transmission mounts causing uneven power delivery, resulting in metal impact sounds during gear shifts. Once, while helping a friend inspect his car, we found that the screws on his aftermarket engine skid plate had loosened and were hitting the chassis. If the noise occurs during turning or reversing, worn wheel bearings are the most probable cause. It's advisable to have technicians thoroughly check the torque of chassis screws during each maintenance service, as these areas are prone to loosening but often overlooked.
