Vibration of drivetrain
 

Have a 91 300D 2.5 Turbo. I did a big mistake when i changed the middle support bearing.I didnt mark the driveshafts and now i have a bad vibration.Anyone have a idea on how to get them back in balance or is there any marks to go by? Thanks

I did the same thing on my truck when I changed out u-joints. You could experiment with 90 degree adjustments, until you get it vibe free.

keep trying
 

If this is anything like the 300SD with flex joints at the trans and diff, the three legged drive flanges (tripods) must be in line when looking down the length of the shaft. This means there are ONLY three ways to assemble the shaft.

Good luck and keep trying, been there and done that.

Steve

The lining up of the ends is what I have been told also.

But on a 1991.... there were supposed to be marks put in by the factory
to help realign, they are either stamped marks (punch marks) or small tabs.
These would be where they join at the bearing.

Agree- your shaft should have been marked by the factory. Check the service manual for what they look like. On the W123, they're sort of arrows cast into the flange close to the ujoint journals, IIRC. Not really easy to figure out unless you know what to look for.

I also have a driveline vibration in my 500 SEL (I know, not a diesel). After reading this thread I checked the driveshaft alignment. The factory marks are lined up, but the tripods don't line up. In reference to the front, the rear is off by 60 degrees or half way between the front (does that make sense). I checked a driveshaft from an 87 SDL and it was the same as mine, the marks line up and it also had the same vibration. I haven't had a chance to check my 91 300D yet but I will because it is as smooth as silk. Is it possible that these marks should be 180 deg apart which would line up the tripods? By the way, My 500 has new center support and bearing and new flex joints. None of which helped. The center joint doesn't have any roughness in it as many do, and the individual shafts have been checked for balance. The shop couldn't do both shaft when put together. I sure would like to get rid of this vibration. Any ideas?