I just bought a 1975 240d (115 chassis with 2.4L N/A) and was/am super excited about it. My alternator belt crapped out on me which in turn disabled my waterpump and the engine overheated. I don't believe anything major was damaged. Changing a belt seemed to me like a pretty minor deal, I've done it on countless other cars with nary a real headache. But after fidgeting with this Mercedes pulley system, I started wondering if MB intentionally made things difficult so you would have to take it to the dealer. To get to the alternator belt, you have to take off the other belt (is that other side running a vacuum pump or power steering?) I found three bolts on the front of that other side and one on the back. I loosened all of these and the pulley got looser but not loose enough to get the belt up and over. The alternator flanges have two bolts on the front and then another hex head that is also a cog. I assume this cog is how you put tension on the belt. On the backside of this cogbolt is a nut that I loosened (I assume that once loosened this cog can be rotated out or in by turning the hex). After loosening the back nut that cog still won't turn. This is all complicated by the AC unit that is attached directly above the alternator in my way.

So could anyone explain this system to me? Am I missing a basic notion of how this works? The old slide plate design sounds like brilliance right about now.

I also went to Napa today to inquire about a Chilton or a Haynes manual for this car. They looked it up and couldn't even order one for me. Plenty for the W123 but the venerable W115's seemed to have reached obsolescence in the Chilton/Haynes world. I have read about the cd you can buy on this forum, but $115 seems a bit steep to me. Are there other manuals out there anyone can recommend?

Thanks