Some will say to roll the belt on without loosening the adjustments. I strongly recommend not doing that.

The 300D engine compartment is a Bear to work within, but the compressor is not too bad if you work from underneath and from the top. A set of ramps would be really helpful.

There are the three large bolts and then there is an adjuster below the power steering pump that you can use to loosen and tighten the pulley position once the big bolts are loosened.

It's been awhile so I don't remember exactly what ratchets, extensions, etc. that I used, but it seems that I remember it taking nothing more than a ratchet, socket and box end wrench. If you have a few different extension lengths, they might come in handy.

As far as putting the wrenches in place and twisting, we can't help you very much over the internet with that part, but get determination in your mind and a few wrenches in your hand and you'll get through it.

Good luck,

For cryin' out loud, can't the website administrator fix this damned clock/time thing? I hate it when posts appear out of order...! :mad:

About the problem though, I'm with Larry. This is NOT a fun or easy job. No special tools are required though, just lots of patience and elbow grease... :(

so I do have the right 3 bolts, 19MM, located in back of the compressor. They are really a ***** to get at, I can get tools on 'em but nowhere to move. Patience is a little thin right now but I'm gonna sit back and pense upon this for a while and tackle it again. Miserable job this.

On the A/C compressor, you can put a long 19mm combination wrench (use the box end) on the bolt then take another combination wrench and hook it into the open jaws of the first wrench so you can in essence use it as a "cheater". This will give you the leverage you need to get the bolts loose.

NEED HELP A/C Belt
 

83 300D
How the hell are you supposed to change the A/C belt? I've located 3 19MM bolts on the back side per the service CD. How are you supposed to get these loosened. Can't seem to fit anything in there that allows me to apply any torque. Is there some easier way to get the belt off and on? Should I be using some special tool. I have to changes all my belts since one of the double belts for the alt and water pump is missing and all are squealing a lot. Think this is a big part of my running hot problem. Any help/guidance greatly appreciated. THANKS.

YES !!!! That sucker's outa there and the right way. 19MM box, little 10 MM stubby for the adjuster. Took off the rubber gloves, got down-n-dirty and got the thing out. All that's left is the alt belt and put it back together. Guess I was getting a bit panicky being this is the first work of the new car fixit season. Thanks for your help and encouragement guys. Going to be an interesting summer fixing up this old beast.

ALRIGHT!

It's all about attitude. You just go at it with determination and you will get it done!

Good work,

Good for the damn A/C, Had to post again for the alt belt. Really thought that'd be the esy one, WRONG!! Then I found out that performance products shipped the wrong belts. Very disappointing first of the season task :-(

Thanks to this group and to FastLane the all 4 belts are now renewed in my 83 300D. Not a ridiculous job once one knows where to loosen things. The entire swap took 2.5 hrs and I didn't even take off the fan. Next work is the valve adjustment. Just did it on my gas 220s so I'm at least in the mood.

This was a very helpful post. I just finished changing out the A/C belt on my son's 300D last night. I would have had a great deal of difficulty without the helpful hints posted here. It made the job a lot easier and faster. I think we finished in about 1.5 hours. The biggest problems was just getting the nuts to break loose. Thanks to all who contributed. :)

rmmagow:

I just recently changed out all my belts as well after the A/C belt broke (dissentegrated).

I agree, the worst part of the job was all the time spent LOCATING the loosening and adjusting bolts. I could've had the job done twice as soon if I'd known where everything was at.

I'm curious though, why did MBZ decide to use TWO belts on the alternator and a single belt everywhere else?

The two belts are for the load of the water pump and the alternator. Power steering load is lower and A/c is/should be lower. Car will run w/o A/C or power steering, but won't play nice w/o water pump turning so two belts are insurance.

...but the two belts are on the alternator.
but going with your logic, loss of the alternator woudn't be fun either.

...which all adds up to one more reason to get a newer MB diesel with the OM60x engine! Those all have a nice, simple serpentine belt setup. Piece of cake to work on and zero adjustments. The tensioner assembly has a relatively short life span but that is, IMO, a highly acceptable compromise compared to loosening the AC and PS systems so you can fiddle with the alt/WP belts! I replaced all 4 on my W123 and hope to sell the car before I have to touch any of them again (ugh!) :cool: :cool:

I want to thank the poster who described the 10mm bolt for adjusting the air compressor posistion. The 10 mm bolt was not obvious to me, and therefore I'm highliting it.

Also, I needed to use a big screwdriver (closer to hoses than I liked) to get the leverage to move the compressor sufficiently to put the new belt on.

Thanks for the assistance on this!!!