Some vehicles have two drive belts, but most modern vehicles have a single belt, called a serpentine belt. It’s a reinforced, ribbed rubber belt that delivers power to your alternator, air conditioning, power steering, cooling system, and other components in your vehicle. Usually, these belts don’t require maintenance, and will last up to 150,000 miles. Of course they’re not going to last forever, and once they fail, your vehicle isn’t going to go anywhere. That’s why you should have regular inspections, and have your drive belt replaced if you notice any problems.
So, how do you know if you need to replace your drive belt? Here are a few clues.
Noisy drive belt
This is the biggest tip off that you have a drive belt problem that shouldn’t be ignored. If your serpentine belt is squealing, it’s time for an inspection. Maybe it’s just water on the belt, which isn’t a huge issue. If you’ve been driving through torrential rain, you can expect some squeaking. But if the squeak is due to leaking or spilled motor oil, that’s a whole other ball game. Oil is the kiss of death to the belt, so make sure you don’t have any leaks, and have YourMechanic replace the belt right away, instead of waiting until the inevitable damage forces you to have it done.
Before your belt fails, it will usually show signs of wear. If the ribs facing the pulley are missing chunks, it’s not necessarily the end of the world. Many belts will function quite well with a few bits missing. But if there are a lot of chunks gone, or if several notches appear close together, replace the drive belt right away – this is just a disaster waiting to happen. If one side is wearing unevenly, you could have a misaligned belt. This could be a problem with the pulley.
Cracks and rot are, of course, indications that you should replace the drive belt. Any crack that’s more than halfway through the belt has to be replaced immediately.
If your drive belt is damaged, don’t take chances. You could drive for miles without a problem, or you could end up stranded by the side of the road. Worst case scenario, a damaged belt could cause extensive damage to other vehicle components. When in doubt, it’s best to replace.
This article originally appeared on YourMechanic.com as Common Signs Your Drive Belt Needs Replacement and was authored by Valerie Johnston.