Stop squealing belts easily in your Volvo by replacing worn mounting bushings. As the rubber bushing wears, the pulley comes out of alignment with the crankshaft and causes the belt to squeal. You can confirm this by inspecting the belts from the driver or passenger side and sighting down the belt to the crankshaft.
These bushings are used on the alternator and power steering pump mounting brackets. Depending on the year and model, you might need three or more to repair your problem. Be sure to check the quantity you need before ordering.