Tech Tip: From Serpentine Belts to OAPs: What to Know About Accessory Drive Systems
This Motor Age Tech Tip sponsored by bproauto focuses on one of the most important yet often overlooked systems in a vehicle — the accessory drive system. Erik Screeden, Technical and Multimedia Content Director for Motor Age, shares how this system converts crankshaft rotation into power for critical components like the alternator, water pump, AC compressor and power steering pump. Screeden explains the role of the serpentine belt, the heart of the system, and why proper belt tensioner maintenance is vital for performance and longevity.
Learn how pulley alignment issues can cause premature wear, squealing or even system failure, and why every part, from the crankshaft pulley to the smallest idler pulley, plays a role in keeping things running smoothly. The Tech Tip also explores evolving technologies such as the overrunning alternator pulley (OAP), which reduces vibration and alternator drag during deceleration, and the advantages of modern EPDM serpentine belts that last longer than traditional compounds.
With practical tips on diagnosis, proper routing and replacement, this Motor Age Tech Tip offers valuable insights for anyone working on or around belt-driven systems. Watch the full video to see Screeden break down common problems, share inspection tips, and explain how to ensure reliable performance from the entire accessory drive system.
About the Author
Erik Screeden
Technical and Multimedia Content Director
Erik Screeden is the Technical and Multimedia Content Director for the Vehicle Repair Group. He has been in the automotive industry for over 24 years. During that time, Screeden was a technician. He started out at a Ford dealership and continued to several independent repair facilities as well as spent time in the specialty aftermarket where he had the opportunity to work at a GM-specific performance shop. After his time as a technician came to an end, Screeden transitioned into a role providing scan diagnostic and J2534 tool support. He was then able to parlay his experience as a technician and a support specialist and use that in several technical sales roles.