Those alternators are also being mated to growing numbers of rough-idling, four cylinder and diesel engines that exert even greater belt - speed changes on the entire system. And if that weren’t enough, car companies are decreasing engine idle speeds in order to increase fuel economy, which just adds more vibration and belt speed fluctuation to the mix.
The end result? A whole lot of screeching, scratching and broken belts, dead batteries and water pump and power steering bearings that break down much too soon.
Clutch, particularly decoupler pulleys, go a long way to calming those vibrations and reducing drive belt and tear... but we’ve gone one better.