This is wrong!
NEVER will I swap out parts just to throw at a problem. I also would not recommend this to anybody. Mr. P.e. Haiges if you would ever say to someone that at 150 k on a motor that there isn't some stretch in a timing chain and this doesn't come under routine maintenance I would be the first person to stand up and say you are wrong! All the Mercedes techs in this forum have said they don't replace a timing chain until it breaks. Now, I know what it costs and know how hard it is to find a aluminum head on a Mercedes diesel engine after the timing chain has broken and a piston has come up and slapped a valve and ruined the head. It would have been extremely less expensive on the owners part to have done the routine maintenance of changing the timing chain. I am not a full time Mercedes mechanic but rebuilding Mercedes engines in my spare time is what I do and I do it with a passion. I would NEVER recommend to anyone if it aint broke don't fix it! This can lead you to a larger cost from your pocket than doing the routine maintenance. How else do you think Mercedes engines last so long?