A V belts are made of predominantly rubber, they will eventually wear out and get brittle. Automotive experts recommend that you replace your belts every three or four years regardless of how they look upon inspection.
How to Replace Your V Belt
Most alternator moves outward. The belt should be tight enough that you cannot pull or push the belt with your hand at all. Consult an owners manual if there are any more complicated processes involved in removing your old belt.
