Alternator freewheel clutches, also known as OAPs (Overrunning Alternator Pulleys) are a core component of your car’s alternator. You’ll typically find these on newer model vehicles, whilst older models will usually use traditional solid pulleys. The purpose of alternator freewheel clutches is to allow your alternator to freewheel when your car decelerates. This essentially dampens any vibrations that travel to your car’s alternator, protecting the unit more than a solid pulley would.
It’s difficult to diagnose a fault with your car’s alternator freewheel clutch, however a common sign is the presence of a short chirping noise when you start or shut off your car’s engine. If you suspect that your pulley needs changing, you should get this confirmed by a professional before undertaking any repairs.
We stock a range of alternator freewheel clutch pulleys at Parts for All Cars, shop them all below.