Serpintine belt

[JohnnyLou]

Hi, can any members give me some advice on renewing a serpentine belt on a 2008 S204 C class 220 tdi estate, I understand the basics of fitment but can't see the 'lug' that you have to push forward to relax the pulleys that the belt runs on, any tips please would be much appreciated ....

 

[MancMike]

On my different engine, it's the tensioner pulley. There's a big 22mm nut in it, obscured by the pulley itself, you get a breaker bar on it and lean it over, relaxing the tension.

 

[AMGeed]

Scroll down to Step 3 in the following "How to"
Mercedes Crankshaft Pulley / Harmonic Balancer DIY ? MB Medic

There is a video that follows Step 3 that shows the whole process.