Some things that cause a vehicle's front end to make a clunking noise are worn ball joints, a damaged tie rod, broken or loose sway-bar links, hard or damaged shocks, and faulty shock mounts. An automotive professional can inspect the vehicle's front end to locate the source of the clunk.
Other possible causes of front-end clunking are loose or hanging brake calipers and worn or warped brake rotors. When possible, avoid driving a vehicle with a front-end clunking noise. Any of the issues listed above that cause a clunking noise are critical components of the vehicle's suspension system, and failure to repair them may lead to further damage to the vehicle, accidents and personal injury.