I'm going to chime in here and declare a pox on everyone who had a hand in the design of the belt tensioner on my '90 300E. If the tensioner goes out on either of my 150K plus miles GM products, I purchase a new one at nearly any parts store for what I think is a reasonable price and spend about 15 min (with NO removal of any other part required) installing it. When it went out on the Benz last week I spent nearly $200 for the tensioner and dampener (my adjuster rod was in good shape) and then went through about a 2.5-3 hour ordeal that included removing the radiator, the water pump pulley, the power steering pump pulley, the fan pulley and the bracket that holds the tensioner in place. Of course after all the removal of parts, installing the tensioner itself is like putting panty hose on a bobcat and then the aforementioned parts have to be reinstalled and the cooling system refilled. I love my Benz and truly believe it is a driving experience like no other but no sane person can think that this is the best (or even a good) way to run an accessory belt system!