Description:

How does the overrunning alternator pulley work: When the overrunning alternator pulley is rotated in the normal operating direction it connects to the alternator working as a normal pulley. But during deceleration the pulley disconnects from the alternator shaft, allowing the alternator to free spin. This is done by a special one way bearing that is mounted inside the overrunning alternator pulley.. Advantages of using a overrunning alternator pulley: Heavy duty designed for long service life Dampens drive belt vibration Reduced belt slippage during rapid acceleration or deceleration Reduced stress on drive belt and other accessory drives Increased alternator and drive belt life Reduction of drive belt noise Improvement in variation of drive belt tension. Signs of an overrunning alternator pulley failing: Unusual drive belt noises Unusual vehicle vibrations Steering shudder Alternator not charging battery. Checking the overrunning alternator pulley: Remove drive belt Check pulley for chips, dents or damage to belt grooves Check for excessive bearing movement Rotate Alternator pulley in normal operation direction, pulley should lock up and turn alternator shaft Rotate alternator pulley in opposite direction, it should spin freely without the alternator shaft moving Rotate the pulley in the free spin direction, it should feel smooth not rough.