clunking

Clunking is a term used to describe a loud, hollow impact-like noise or sensation that occurs when a mechanical system has a loose, damaged, or misaligned component. The noise is often irregular and may occur during acceleration, deceleration, cornering, braking, or while going over bumps, depending on the part involved.

Common sources in road vehicles include driveshafts and constant-velocity joints, wheel hubs, suspension components such as ball joints, control arms, tie rods, and sway-bar links, engine or transmission mounts, exhaust hangers and heat shields, or loose wheels and lug nuts. In machinery, clunking can arise from loose belts, misaligned pulleys, worn bearings, or damaged couplings.

Diagnostics typically begin with a visual and manual inspection of mounting points and components for looseness, wear, or damage. A road test helps locate the noise source by reproducing the condition. Tools such as a mechanic's stethoscope, torque wrench, and diagnostic trouble codes can aid. Replacing worn parts, tightening fasteners to specification, realigning components, or mounting new engine/transmission mounts often resolves the issue. In some cases, balancing wheels or repairing exhaust components is required.

Unsafe driving may result if clunking is caused by a failing drivetrain or suspension component; if unresolved, it could lead to loss of control or additional damage.