Belt and Tensioner 96 W210 E320

[scjim]

I just came from the 45,000 mile service on my 1996 E320 W210. Everything was in great shape, but the tech said the accessory drive belt was showing signs of age, some small cracks. They recommended that I change the belt and tensioner at a cost of $365. I think I can do the job myself. There is no noise from the tensioner or belt. They said because of the age they would recommend tensioner replacement. What do you fellows suggest if age is the criteria. If the tensioner fails would the bearings in the pulley fail and let the pulley go flying to do it's damage? Would you hear the bearing squeal sometime prior to this catastrophe?