Crankshaft Pulley Vibration Damper
Volvo call the pulley ‘an oscillation damper’ and the rubber insert is built in. The problem comes when the rubber stretches and allows the metal to move on its own. There is a possibility that the outer metal part will fly off and cause untold damage to the car. This is a possibility and I have never heard of it happening but I haven’t spoken to every 240 owner 🙂 .