Dayco Pulley MountsWhy just replace the pulley, when the pulley mount is worn or damaged? Designed as a heavy duty replacement, Dayco Nuline idler mounts are made from high quality material and manufactured to tight tolerances. These mounts are fitted with quality pulleys made from an all metal construction using high speed bearings with nylon cages and ETK grease, for quiet running and extended operating life.Common Causes of Failure:Seized engine pulley retaining bolts leading to mount breaking on bolt removalEngine pulley bearing failure which can also cause damage to the pulley mountWorn mounts can cause misaligned pulleys and incorrect belt trackingOver torqued pulley bolts leading to stripped threads and cracked mounts