Hi,
OK, Tight on time to read all the posts. I have had a C230 and SLK 230 both with the same M62 Eaton supercharger and electro. clutch pulley. Note the newer SLK models have a M45 supercharger with no clutch pulley, and what I'm mentioning does not apply to those. YOU GUYS NEED TO CHANGE YOUR SNOUT BEARING!!!!!! That is what takes the belt load, not the supercharger internal bearings. BUT, superchargers do need oil changes. I use Mobil 1 full SYN. gear oil. I have been using that oil on every Eaton supercharger I have owned which would be about a doz. vehicles. IT'S THE SNOUT BEARING THAT SOUNDS LIKE S#*T, they only last 50-70kmi. Go on Ebay there is a guy who sells them for about $40.