I've been playing amateur mechanic the last couple days trying to replace the belt tensioner on my '87 300e (103 engine 124 chassis). It's most definitely shot. Squeally in the morning, squeally after work. Something needed to be done.

I first tried reasoning with it, but that didn't work.

So then I got some ramps to get up under the front end, loosened the shroud and moved it aside (a one piece variety of shroud, I'm still considering taking a hacksaw to it to get it out of my way), removed the big 19mm bolt through the tensioner, and had to recruit a friend to get the 11mm bolt (in other posts I've read this is listed as a 13mm bolt, but the head on mine was most definitely 11mm) that went through the tensioner's swivel hole. The nut on it was totally loose, and the washer behind it is what I hope was making the worrisome rattling noise up front. I could see, looking up from under the car, that the threads on the 11mm bolt were roughed up, and in fact were what kept the nut from falling off altogether. It looked like the classic case of someone not loosening the 19mm bolt before loosening the 11mm bolt before changing the belt (it does have a newer belt).

We managed to get that bolt out of there, and even with those two bolts removed the belt was still tight in there. I could bend it some, but wasn't able to remove it until after I beat on the old tensioner a little bit hammer and chisel style to loosen it up a bit.

Now I have to remove the plate in front of the tensioner, but to get to one of the bolts securing it I have to remove the power steering pump pulley wheel. It appears there are 3 bolts securing it to a flywheel on the power steering pump.

My main question is this, what direction do I use to twist those 3 bolts off of there? CW or CCW? Usually CCW to loosen, CW to tighten, but I was told sometimes pulleys are different in that regards. Also, I've read that I may need a special pulley tool. Is that true? I have a strap wrench to secure the wheel while I tried the bolts both ways, but I didn't get a budge. I was afraid to give it my all (which is what it's taken to get other bolts loosened on this car, along with an accompanying flesh wound) without being sure which direction to twist. I know I've read here that you can remove those bolts and lightly knock the pulley wheel from the power steering pump, but I want to make sure I'm barking up the right tree.

I'm also going to need a new 11mm bolt. I can use the hole on my new tensioner as a thread pitch determining guide, but I'm wondering if there's a special bolt I need to order.

I've also read that I need to apply RTV sealant somewhere when putting on the new tensioner, but where exactly do I apply it? I'm guessing on the 19mm bolt, because it's the only thing I've taken off so far that's long enough to get to an oil passage, but would I apply that at the end or under the head of the bolt?

The new tensioner is getting impatient, but I was able to reason with it, and it's now sitting quietly awaiting my efforts.

Thanks