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.
The main cause of power steering noise is low power steering fluid level. The sound may be a whining sound that occurs upon turning the steering wheel. The power steering pump requires hydraulic fluid to aid in steering. The car should have a dipstick to check the power steering fluid level.