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.
If a vehicle makes a whirring noise only upon deceleration and consistently makes this noise at any speed, it is likely that it has bad pinion bearings or is suffering from a loose pinion bearing preload, notes West Coast Differentials. Worn rings or pinion gears often result in howling and whining upon acceleration. Improperly set up gears may also cause these symptoms. A whirring or rumbling sound occurring at speeds over 20 miles per hour is typically the result of worn carrier bearings. If the sound changes when turning, differential failure from worn carrier bearings is most likely.