Drive Belt Change- Stuck at the Alternator. Assistance needed - PeachParts Mercedes-Benz Forum

tsw27 · #1 09-01-2008, 10:48 PM

Hi All,
Woke up today and thought what a great idea it would be to change my drive belts. I have change them on every other car I have owned, so I thought no big deal. I did some research here on the site and went to it. I started about 1:00pm it is now 8pm and I am stuck. What a friggin nightmare.

I got the AC belt and PS belt off no problem. I finally got the alternator loose enough to get the first belt off, but I couldn't get the second belt over the 1st shiv/groove. I ended up cutting this off thinking no big deal.

I commence to put the belts back on and this is where I ran into a brick wall. It seemed as if the alternator was loose enough to get the new belts installed. I began to put the 1st belt on the pulleys trying to get it all the way over to the shiv/groove closet to the generator but the darn thing slipped into the second groove. I thought, no prob I will just slip the next belt over that and be on with it. Well there is just far too much tension to get the second belt on. And guess what...there is too much tension to get the first belt off and start over. No matter what I try I cannot seem to get enough slack to move these belts.

Anyone with experience willing to share it would be great. I am an ok home mechanic and am trying to save a few bucks by doing this seemingly routine project on my own. I have just never ran into an alternator mounted quite like this. How in the world does a person create enough slack to get both belts on? I am really stuck here. Please, anyone with tips or help or whatever throw me a bone.

Regards,
Thomas

Jeremy5848 · #2 09-01-2008, 11:03 PM

Please tell us what kind of a car you have and we will try to help you.

kerry · #3 09-01-2008, 11:12 PM

I believe you are not the first person to run into this problem. My recollection of threads about this topic is that there are different sized belts, some of which are impossible or next to impossible to install. I suggest getting slightly longer belts. This assumes your adjuster is loosened as far as possible

tangofox007 · #4 09-01-2008, 11:21 PM

I bit of research suggests the car might be a 1984 300D.

If that is the case, you could remove the water pump pulley to gain some extra slack on the belts. That, however, could cause additional complications if you don't have a 10mm box end wrench thin enough to fit the fan bolts. (The bolts are easy to round off with an open-end wrench.)

tsw27 · #5 09-01-2008, 11:28 PM

Ah yes, sorry, 1984 300D is the car. I thought it was in my signature.

pawoSD · #6 09-01-2008, 11:36 PM

What size belts? Did you adjust the alternator tensioning bolt all the way in to get the alternator as close as possible? When I did that it seized on the rusty bolt and broke.....4 hours of struggling later I got it back on with the leftover threads. Not a pleasant time.

raslaje · #7 09-01-2008, 11:55 PM

I uploaded "Renewing and tensioning of V-belt" 13-340 of the field service manual on zSHARE.

13-340.pdf - 0.93MB

tsw27 · #8 09-02-2008, 12:19 AM

Thanks for the pdf file. It should do me some good tomorrow. Here is a thought: What direction is the tensioner nut turned to create slack? I read in a thread earlier today that in needed to be turned anti-clockwise, should it be turned clockwise?

toomany MBZ · #9 09-02-2008, 06:24 AM

I believe it is anti-clock wise to loosen. Many times the wrong size belts are installed, but work.
Good luck.

tsw27 · #10 09-02-2008, 06:59 PM

Thanks to everyone who responded. With your help I was able to figure out what was holding me up. Sometimes I am just a big ol' idiot. It turns out that I misunderstood what needed to be loosened on the alternator, or better how the adjuster nut needed to be loosened. I cannot tell you how easy the rest of the job was after I got the adjuster assemble loose.

What a relief and my wife now has her car back.

This was pretty much the last thing that needed to be done as far as maintenance goes. Over the past month or so we have fixed the Vac system, new tires, complete interior detail, new AC system and some other things. I am happy to say ol' Josephine is running about as good as ever. We did all of this work because we were thinking of selling, but now... I dunno... she could go another 180K miles easy.

Thanks again for your help.

Regards,
Thomas

tobybul · #11 09-02-2008, 10:21 PM

Just read the thread Tom. I just did this on my 85D since I had to replace my alt. Looks like you are done but for those who may have to do it next time.... if you loosen the alternator belt tensioner (CCW) as far as you can loosen it, it will loosen the alternator belt to the point that you can slip off the 2 alt belts. And yes, the power steering and ac belts have to come off too since the alt belts are in the inner most side ( I replaced all the belts while I was at it).

I did this 2 weeks ago and I retightened all the belts again yesterday since all the new belts settled and were slightly loose.

bmac8369 · #12 09-16-2008, 09:42 AM

Quote:

Originally Posted by raslaje

I uploaded "Renewing and tensioning of V-belt" 13-340 of the field service manual on zSHARE.

13-340.pdf - 0.93MB

Thanks for posting this. I have the memory of a sugar ant!! I took my belts off and couldnt remember the configuration. Time to get this 300SD back on the road.