Serpentine belts have had the same function for decades: powering the various engine accessories like the alternator, air conditioning compressor and such. The type of material used to make serpentine belts has quietly evolved; so quietly that many St. Thomas drivers don’t know about it. The trouble though is that many are looking for the wrong signs of belt wear.

At one time, cars came from the car maker with neoprene belts (there are still neoprene replacement belts) similar to the material used to make wet suits. When these old style belts wore, they would often get shiny or glazed. They would develop cracks. St. Thomas drivers knew their belts needed to be replaced if they had three or more cracks in three centimeters or if they had deep cracks.

Modern belts are made from EPDM (Ethylene-Propylene-Diene-Monomer for you “science geeks”). Small cracks in EPDM belts are normal and will not influence their function. EPDM belts last much longer than the old neoprene belts. Wear on EPDM belts is determined by measuring the wear in the ribs and valleys on the serpentine belt with a simple tool. Once 5% of the belt rib material is lost to normal wear, the belt should be replaced as it is not functioning at optimal capacity and can actually allow slippage that can cause damage to the accessories.

If you search this concept on the internet, you’ll find a lot of the recommendations for belt replacement that are based on the old neoprene belts – so you’re more up to date than those sites are. In the event that you hear a squeal or chirp from you engine compartment, especially at start up, a serpentine belt replacement may be necessary.

At The Auto Guys in St. Thomas, we can inspect your serpentine belt system for belt wear, belt alignment troubles (belt abrasions), pulley troubles, and belt tensioner issues. Your belt tensioner, which keeps the serpentine belt tight, has the same service life as the belt itself so they should be replaced together along with the idler pulleys.

Ask your The Auto Guys service advisor if it’s time to replace your serpentine belt.

Stop by give us a call.

The Auto Guys
135 South Edgeware Rd.
St. Thomas, ON N5P 4C4