Difficulty Level

What components can cause issues:

• no grease, therefore no lubrication which can either cause the bearing to burn out or seize up
• the bearing cage can break
• worn bearings, therefore causing play

What to look for:

• squeaking or chirping when the engine is running
• wobbling on the pulley when it is turning

Tests which can be done:

• when the engine is running, watch the pulley for any wobbling or wandering
• which the engine off, wobble the pulley by hand, sometimes this can be done with the belt on, but it's much easier when it's off
• removing the belt, spin the pulley and listen for noisy bearings
• remove the pulley and simply shake it to listen for loose bearings