All of it. The 10 percent figure you occasionally see is nonsense that a lot of people believe just because they've seen it so much.
Quick Answer. 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. Continue Reading.
POSSIBLE STEERING PROBLEMS AND CAUSES. NORMAL NOISES. You or the driver may hear a hissing noise from the control valve when it is actuated during a steering maneuver. You or the driver may hear a noise as fluid bypasses through the poppets at full turn. You or the driver may hear a noise from the system relief valve when it is required to actuate.