How often should I replace my belt? Well that depends- fashion accessory or alternator drive belt? The fashion accessory belt probably seasonally unless of course it’s a classic black leather number with a fashionable silver buckle, that one lasts for years.
The alternator belt however is another story. Most vehicles have a rubber “accessory” belt on the front of the engine that drives the alternator, power steering pump and A/C compressor, possibly even the water pump depending on year make and model. If your drive belt (sometimes called a serpentine belt) breaks it will render your car un-drivable. The A/C compressor will not be able to run (this of course means it must be August. The power steering pump cannot operate- which means no power steering assist (this of course means you are on a curvy mountain road). The alternator cannot charge the battery and the water pump cannot circulate coolant through the engine (this of course means you are in the middle of nowhere). So don’t let this happen to you. Manufacturers recommended replacement mileage varies but if your car has more than 50k- have it inspected by your repair shop at each service visit.
So how does the technician determine when to replace the belt? Today’s modern belts are made from ethylene propylene diene monomer (WHAT?). This is a synthetic rubber that typically lasts longer than the older types of engine belts. A professional technician will be able to determine if the belts are in good shape or if it is worn and the grooves hidden on the underside of the belt have worn too wide or deep. Worn belts will cause the belt to slip on the pulleys that drive the accessories in turn causing reduced performance or failure of those accessories. The belt also must be under proper tension, most newer cars have an automatic belt tensioner that does not need to be adjusted. Manufacturers design the tensioner and belt as a system so they “wear” at the same rate. Often drive belts are replaced as a kit with a new tensioner and hardware. It’s also a good idea to replace an old drive belt when an alternator or any other accessory component driven by the belt is replaced. At Mike’s KARS we take a peek at your drive belt every time you stop in for any service so you don’t have to worry about a break down in August, on a curvy mountain road or in the middle of nowhere.