DriverSide's Car Dictionary has the most comprehensive definitions of automotive terms. This auto glossary can help you decipher what your mechanic is fixing and what the purpose or function of the particular auto part or accessory is for. We have taken the mystery out of automotive service jargon, so that you don't have to.
A lobed metal shaft in the cylinder head that causes the valves to open and close. These do not wear unless something is tragically wrong in the engine, and are often replaced with more "aggressive" camshafts for improved engine performance.