|Over the past two decades, Dayco has maintained that serpentine belts should be replaced when an inspection revealed 4 cracks per inch, chunking, rib glazing, backside wear or splitting. Using these criteria, identifying worn serpentine belts was a straightforward process. The belts in this time frame were made from Neoprene compound and were expected to last approximately 50,000 to 80,000 miles. |
Today’s belts are now made with an EPDM extended-life rubber compound. These EPDM constructed belts wear completely different than Neoprene, and can last up to 100,000 miles. EPDM belt wear can be difficult to detect because the belts tend to wear like a tire, i.e., there is a material loss from the ribs. A new EPDM belt will have a traditional “V” profile in the ribs. With worn EPDM belts however, the “V” profile has the appearance of a “U” instead, because of the material lost from the rib. Once the rib profile is changed, there is less material (and therefore less surface area) coming into contact with the pulleys. This material loss can cause slippage that will affect the performance of the accessories and possibly result in an annoying noisy belt.