Accessory Drive Belts

Fiber reinforced rubber V-belts were the standard means of accessory drive for most of automotive history, and most cars used just one belt to drive the water pump, fan and generator. Then, with the proliferation of accessories like power steering and air conditioning, and emissions equipment like air pumps, 2 or 3 belts became necessary, which took up additional room in ever more crowded engine compartments. A better accessory drive system was needed.

That improvement came in the form of the serpentine belt, also known as the V-ribbed belt. Today, a single serpentine belt, along with idler pulleys and a tensioner, can drive all of a vehicle’s accessories. Along with being more compact, a serpentine belt system is also less maintenance intensive. Unlike V-belts, which require periodic adjustment, most serpentine belts have spring loaded tensioners that automatically maintain belt adjustment.

But all accessory drive belts, even serpentine belts, eventually wear out and must be replaced, and belt drive systems can often be the source of noise that indicates particular problems. Inspect belts for damage like fraying, chunking, glazing, contamination from fluids like oil or other damage that would be an obvious cause for replacement. Evidence of cracking was a clear indication of the need for replacement on V-belts and older neoprene serpentine belts, but this is not a clear determinant of belt condition on the newer serpentine belts made from EPDM (Ethylene Propylene Diene Monomer) rubber.

EPDM serpentine belts lose material as they wear. The peaks of the ribs wear down and the V profile becomes more like a U, which results in less belt contact with the pulleys and belt slippage. Inexpensive gauges are available that can quickly show the condition of an EPDM serpentine belt. Problems in the belt drive system can also cause belt wear and noise. Misaligned pulleys can cause a chirping noise and create heat in the belt and accessory drive pulleys. A bad tensioner can cause belt slippage, belt squeal, and also cause the belt and pulleys to heat up. Heat will decrease the lifespan of the belt and pulley bearings.

No matter what type of accessory drive system you have on your car or truck, we have the parts for the repair. We have V-belts and serpentine belts for all applications, including double-sided belts for when power transmission is required from both sides of the belt. And if you need to replace more than just the belt, we have time and money saving kits containing the belt and the required tensioners and idlers. We even have the latest in serpentine belt design, self-tensioning “stretch belts”, which were created for specific applications and don’t need an automatic tensioner or periodic adjustment.