Q: Why my drive belt keep shredding ?

Usually, by the time a Mercedes drive belt is ready to be replaced, the tensioner is shot too. If you haven’t replaced the tensioner, than you should. If the pulley that was replaced was in fact tensioner, then you need to look at the individual devices. If you have an AC compressor or an alternator that is trying to lock up, the extra load on the belt will make it slip, and eventually burn up. Additionally,if any of the mounts are loose, causing alignment issues, then the belt will not last very long. As a final thought, make sure the routing of the belt is correct. Some of these belts are routed like a Rube Goldberg mousetrap and it’s possible to fit the belt up in several ways, but only one of them is right. If you decide to delegate this work, you can contact Your Mechanic to have a technician come out to your home or office to check out your car and take care of your belt for you.

A drive belt will typically shred due to one of a few different issues. A component that the belt drive has failed (ie: power steering pump, alternator, a/c compressor, etc.), some kind of foreign material has gotten into the belt and caused damage, or a idler/tensioner has failed and allowed the pulley to either lock up, or will allow the pulley to wobble. When the pulley wobbles (which is usually due to a bearing failure) it will cause the belt to come out of alignment and ride over top of the edges of the pulleys and can cause damage or failure. It is normally necessary to remove the belt and do some diagnosis on each of the driven accessories to identify which one is causing the issue. If this is something that you need a hand with, contact a certified mechanic, like the mobile mechanics available at YourMechanic.com.