What’s the best serpentine belt brand?
Don’t assume all serpentine belts are the same! They’re not. Many companies sell serpentine belts. But what’s the best serpentine belt brand? Well, some companies manufacture the brands they sell, while others simply private label and resell belts made by other companies.
Why is serpentine belt quality so important?
If you stare at the pulleys on a running internal combustion engine you’ll swear that the engine is rotating smoothly. It’s not. An internal combustion engine runs in power pulses, each pulse the result of a combustion event. Every time there’s a power pulse the power transmits to the belt and the belt transmits the power to every driven component. Between power pulses, the spinning driven components tend to slow down, placing a drag on the belt. The alternator rotor, for example, weighs about 10-lbs and causes significant drag on the serpentine belt between each power pulse. The AC compressor causes a different kind of stress as the AC compressor clutch cycles on and off. So there’s always a pull/drag movement in the belt.
Each power pulse and drag event stresses the tensile cords in the belt, like snapping a rope and then releasing it. That pull/drag event causes the belt to vibrate. In addition, the pulses wear the micro “V” sections in the belt. A low quality serpentine belt wears out faster, produces more noise, transmits more power pulse vibration to the driven components and prematurely wears out the automatic belt tensioner.
To understand how a belt tensioner dampens power pulses, click here.
How are serpentine belts manufactured?
Early serpentine belts were made with neoprene rubber on the
back and bottom with polyester tensile cords molded in the middle like a peanut butter sandwich. Neoprene rubber tends to age when heated. The heat causes the rubber to crack. For decades, DIYers and shop technicians judged the condition of serpentine belts based on how many cracks they found in the belt ribs. Neprene serpentine belts last less than 50,000 miles.
Starting around the 2000 model year, car makers switched to serpentine belts made with ethylene propylene diene monomer (EPDM) rubber. EPDM belts don’t crack, are quieter and reduce noise and vibration transmission. They last almost 100,000 miles. But they do wear and you can’t judge the condition of an EPDM belt visually. You must use a wear gauge. See this post
What are the major serpentine belt brands
Gates, Dayco, Continental and Bando
Are there different quality levels?
Yes. Neoprene belts are the lowest quality. EPDM belts are a step up. EPDM belts with Aramid tensile cords are top of the line. Armid tensile cords further reduce pulse stretch, noise and vibration transmission.
Rick’s picks for best serpentine belt brand
I think Gates aramid and Dayco aramid belts are the highest quality belts. Gates and Dayco aramid belts cost about $6 more than a comparable EPDM belt with polyester tensile cords. I think they’re worth it.
If Gates and Dayco aren’t available, choose Bando or Continental. My advice is to avoid all private label store brands. Who knows who makes them? Who knows what they’re made of?
©, 2018 Rick Muscoplat
Posted on by Rick Muscoplat