Good morning.

Maybe you guys can help me with a problem that I have. I recently changed on my 300d (260000 miles) the drive belt tensioner, pulley and damper (basicly everything except the coil), and I changed them at a good MB mechanic about 2 months ago. After driving it for about 3000 miles I noticed that the belt is slipping slowley of the pulley , coming towards the radiator. That is the reason I changed it in the first place, after I bought it I noticed that the pulley was so warn off that the belt cut a rim on it and the ballancer was sitting at an angle.
I talked to the mechanic and I am going this weekend back to see what he can do because it is still in warranty, but I would like to ask for your input also, maybe is something else he missed.

I checked all the other wheels on which the belt is running and there are all alligned. Maybe there is a washer that needs to be behind the ballancer to push it a little forward.

Thank you.

The only washer I know of is between the tensioner arm and the engine front cover. It's 2-3mm thick so not having it should be obvious when you check that all pulleys are in the same plane.

The washer looks like part of the tensioner arm. Very easy to forget to move it to the new tensioner arm.

I find Goodyear Gatorback belts are more resistant than others to pulley misalignment and getting thrown off. That's no excuse to ignore the underlying problem, though.

Sixto
87 300D

Thank you for the reply. I did check with my mechanic today and it seems I am missing the washer, so I am taking the car back to the shop on Saturday for add it.

We got the tensioner out and installed an original MB washer, so I'm hoping the problem will go away.

I'll keep posting if problem persists.

Thank you