The majority of all new cars have them. So you’ve likely heard the term OAD, referring to an overrunning alternator decoupler pulley.
What’s so important about an OAD? An OAD is an alternator pulley featuring an internal torsion spring and a one-way clutch mechanism. So not only will it allow the alternator to free-wheel under engine deceleration, but it also will absorb the constant rapid acceleration and deceleration forces that occur due to changes in crankshaft speed.
The benefit of an OAD is a smoother and quieter belt-drive system, resulting in reduced noise and vibration in the cabin, as well as increased fuel economy. It also will extend the life of the belt, the tensioner, and all driven components by eliminating belt, flutter and slippage.
The OAD performs such an important role that when it’s time for belt service, if your customer is replacing high-mileage components and purchasing a tensioner or idler pulley, it’s a good idea to recommend a new OAD.
To protect all the components of the belt-drive system, it’s important to note that if the vehicle was originally designed with an OAD pulley, a solid pulley should never be used as a replacement.
This video is sponsored by Continental.
