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 removal
• Engine pulley bearing failure which can also cause damage to the pulley mount
• Worn mounts can cause misaligned pulleys and incorrect belt tracking
• Over torqued pulley bolts leading to stripped threads and cracked mounts