Hi guys it's my first time on here so please excuse any mistakes I make. Wonder if any of you can shine some light on alittle problem I got. Basically the bearing on my tensioner pulley keeps failing after a few day's. My car is a 1997 c280 v6 sport. Being a toolmaker by trade I have replaced the bearing several times in last few months with different grades of bearing all to no avail. Ideas would be grateful as the noise from pulley is really annoying