Hello, this is my first post but I really enjoy all the informative information on here. I removed my driveshaft before knowing that is was factory balanced and cannot for the life of me get it back together right. So I'm just going to replace the driveshaft and need to know if there are any sites online that are recommended? I don't have any local shops that I can find so I'm guessing my only option is a remanufactured online driveshaft. I live in Eastern,Ky so if anyone knows somehere close that sells them or online I would greatly appreciate the info. 1985 300cd
Thanks, Kelly

Saw your thread on the gasoline side. If I understand the issue, you've pulled the shaft halves, replaced flex disc(s), identified the match marks and re-assembled the shaft halves with the marks aligned and installed same with a new carrier bearing. Now you have a vibration.

Try putting the car up in the air (lifts are nice but jack stands could work) with the wheels hanging, and spin the tires slowly (by hand - engine off). Look at the tires (lumps, wobbles?), then the half shafts from the diff, then check the D/S. Its quite possible you'll spot the issue (mis-alignment, shaft wobble, binding bearing, mis-aligned flex disc, binding shaft slip joint, etc). Good luck.

When reinstalling the driveshaft, it is important how each bolt, nut and washer is oriented. Also, does your driveshaft have the vibration dampner? Is your flex disc mounted correctly? If the mounting details aren't correct, a new driveshaft isn't going to solve the problem.

Here are a couple of links to help:
Mercedes-Benz Model 123 - Disc 2
http://www.peachparts.com/shopforum/tech-help/235575-flex-disc-orientation-safety-durability-issue.html

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Sam

84 300SD 350K+ miles ( Blue Belle )

I've always used:

Driveline Service of Atlanta in Forest Park, Ga

You can ship it to em ups and they will have it back and balanced with a new u-jt within just a matter of days.

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Jim

On your 1985 you should be able to use the Factory Marks if is a 1985 Drive Shaft; see the pic.
The marks are cast into the parts and are only white in the pic so they are easy to see in the pic.
Although I think the Marks are kind of spaced way far apart just to eyeball them others have done fine with them.

Was it vibrating before you removed the Drive Shaft?

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84 300D, 82 Volvo 244Gl Diesel

Diesel911, any idea what years they did that? (marks on the d/s). I'm having some vibration after replacing flex-disks on my '80 model coupe (upgraded with an '84 drive train including the drive shaft, diff, etc)

No vibration before the driveline being removed. I now have new flex discs and support bearing. Only thing I can think is driveline. The universal joint did have a catch and I worked with it with a hammer in certain spots and before I installed it it was smooth as silk. I had read somewhere on how to fix it and it did I guess. But I just don't know what to do other than replace driveline.

I read in the FSM that they began the marks in '82 but didn't start using them until later in the model year. I think they said August.

The upshot being that you should self-index the '82 shafts whether they have the marks or not. Anything after that just use the marks.

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1981 300TD 310k miles
1970 280sel 172k miles
1966 230 Fintail 162k miles

"Where are we going? And why am I in this hand basket?"

Actually the Manual has that after Aug 1982 they used those makes to line up the Drive Shaft Sections. See the pic.
Before that date the marks are there but the Factory did not pay attention to lining them up.

That means if His Drive Shaft is original to the 1985 CD the marks should have been used when the Drive Shaft was assembled.

That means if the OP lines up the Marks on the Drive Shaft and is still having vibration the vibration could be cause by some other problem.

Sticking U-joint causes Vibration that Rips up several Drive Shaft Supports turns out to be Rusty Needle Bearings
http://www.peachparts.com/shopforum/diesel-discussion/338641-w123-propeller-shaft-vibration-tears-up-rubber-mounts-replaced-nearly-everything-3.html

In any event anytime you take apart something that can go back to gether in a different position it is always a good idea to make the position it is in, take some pictures or make a drawing (and don't loose it).

If you don't you find youself eventually geting diverted from some job you are on and not being able to come back to it in time enough for your memory to be entirely sure of things.

.

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84 300D, 82 Volvo 244Gl Diesel

Yep, that's the post I followed and the u joint was smooth as silk. So I'm guessing the marks are a little off or the rust has caused another catch with the vibration I'm having now. Probably just going to replace it eventually so I can move on to other areas of the car. No place around where I live can even balance the two piece. Have any of you replaced the driveshaft and where to you purchase it? Thanks for all the advice

The Mercedes Dealer sells new Drive shafts but they are as seperate pieces.

For a regular W123 the long section with the U-joint was like $280 each but that was over 5 Years ago. Don't know what the shipping would be.

However, if the CD Drive Shaft is different that would be a new Ball Game.

You could try a used one or get a used one and send that to be worked on.

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84 300D, 82 Volvo 244Gl Diesel