inetd,

The bolt thru the tensioner does not really lock though. I think it just compresses the rubber bushin inside to stop the tensioner from rotating on the mount from the pressure of the belt in its tightend state. It requires 75NM of torque to do this on a healthy tensioner, not the 140NM that stripped the threads of the Combination Mount.

If the indexing of the S-class CD is the same as the 124, try starting with "05-2110.pdf - Examining and replacing hydraulic valve clearance compensating elements (bucket tappets)." The meat of the procedure is the removal of the camshafts, "05-2200" and all things leading up to that like upper front cover removal, darining coolant, removing timing chain tensioner, etc., etc.. The lifters, or bucket tappets come out with any small suction cup.