Drive Belt: What You Need to Know

The drive belt is a reinforced rubber belt that allows the engine's rotating crankshaft to drive components such as water pumps, alternators, air-conditioning compressors, power-steering pumps or superchargers. Your car may use separate belts for one or more components or hit multiple pulleys with a snaking serpentine belt. Belts are relatively inexpensive items that are best replaced when worn, damaged or simply old rather than after they fail. Serpentine belts in particular, because they power so many components, disable the car completely when they break.

How do I know if my drive belt is bad?
The accessory drive belt (also called a V, or serpentine, belt) drives the air-conditioning compressor, alternator and, on many vehicles, the power steering pump and water pump. If this belt breaks, none of those systems will work. If the belt is cracked, frayed or badly worn, it can slip on the pulleys it rides on, and the accessories it drives won't receive all the power they need, which may trigger a warning light. A qualified mechanic can usually tell by looking if a belt needs to be replaced.

How often should I replace my drive belt?
It should be inspected at least every year on vehicles that are more than a few years old to check for wear, and it should be replaced as necessary. Most automakers call for periodic inspection of the belt, but few list a specific replacement interval. Though these belts often last several years, they can become cracked, frayed or worn on the side that is hidden from view.

Why do I have to replace my drive belt?
If this belt breaks, the battery won't get recharged, the air conditioner won't blow cold air and the power steering will go out. In addition, if the belt drives the water pump, the engine could overheat.

How much should I pay?
The cost of repairs can depend on where you are as much as it does on what you need fixed. To get an estimate for your repair, go to our estimator, plug in your car's year, make and model information, add your ZIP code, and choose the repair you need. We'll give you a range for what your repairs should cost in your area.