Am I shredding my belt?
 

This is a Euro 300D (W124) with the NA 603. The belt was changed ~ 1000 miles ago when it partially shredded enroute to Maine. The shop who did the "emergency repair" said everything was lining up and the tensioner looked fine.

Looking at my belt today, I noticed some shavings on the side. I can also see a very faint line on one side developing. Is this normal or should I be concerned?

http://i37.tinypic.com/292691l.jpg

Is it rubbing against anything, do you have a rough spot on one of the pulleys?

picture is a little fuzzy but looks good. on the side shown. what about the other side of the belt. Here's a description with pictures for checking belt condition. http://www.autorepairfacts.com/maintenance/checking-engine-drive-belts/

Here's some better shots:

http://i36.tinypic.com/2e0qlx3.jpg

http://i38.tinypic.com/2jb43gh.jpg

All I see is dried oily crud on the belt.

Sixto
87 300D

Same here, looks fine to me....the belt on my M103 is much cleaner however. :D

We need to see the other side. Thats the money shot.

From the pics it looks fine to me... When threads start coming off you have a problem :)

-J

Hows belt riding on that tensioner pulley? Is it off the front even a little??? If it is, big problem. The belt must ride COMPLETELY on the tensioner pulley, and the tensioner pulley is only as wide as the belt with very little extra width. If the belt is not entirely riding on that pulley, it will shred in quick order. Ask me how I know this...

It seems there was a couple of different tensioners installed on that engine, and 2 of them got little shims between the tensioner and block. This is very easy to miss, and even 1/16" will cause the belt to shred.

Take a closer look at that and let us know. I dont see front edge of tensioner pulley in your pics, which is reason i ask.

It appears to me that there is some wear/rubbing on the engine side of the belt . . . is that what your talking about?

When checking the engine drive belts, you are going to look for two things with your inspection.

Look for the proper belt tension and look for any sign of wear. (Cracks, frayed edges, or glazed back side of the belt)

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Worn belts (cracks and glazed present)

Good results for drive belts should be as follows:

Visual – No glazing or shiny areas on the back side of the belts, and no dry cracks on the pulley side or between the ribs of the belt. If you can read the brand name on the belt and its not squeeling then it’s probably not loose.

If it's a Continental brand belt (?)
 

That looks like rubber mold flashing. Little bits of left over rubber in a checker board pattern.

Thanks for all the replies. I've been keeping a close eye on the condition of the belts over the past few days and today I noticed the first signs of fraying on the edge closest to the engine. So it looks like something isn't lining up correctly or, as some have suggested, the tensioner is missing its shims.

Being a noob to these cars, I took it over to Wolfgang's in Tenafly, NJ which came highly recommended from this board. After I hear back tomorrow, I will post their findings.

Looks like the pulley tensioner is to blame.