I started to hear a little rattle in the top of my 96 c230 with 85000 on the odometer. I know the time for a new chain is coming but to buy a little time and when the time does come I know the tensioner is one of the replacement parts in this complet job. I would like any information anyone can give concerning the replacement of just the tensioner,is it just screw out screw in or is there things I should be paying more attention to before I start this project?