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.
Whenever a vehicle owner complains of under-the-bonnet noise, it is important to determine the type of noise and under what circumstances it occurs. A solution to a noise problem caused by pulley misalignment is not likely to resolve a slip noise problem that may be caused by insufficient tension. In any case, a noisy drive indicates a malfunction, and appropriate corrective action should be taken to eliminate the problem. Belt noise.