Greetings Gents,
Like many of you, I've replaced all of the rubber components in my driveline just to be greeted by a 30mph vibration from my worn u-joint, now articulating in a new orientation. Vibration ceases past a certain speed, indicating it is not a balance related issue.
So the U-joint "indexes" dead center and has an even notch in the four cardinal directions. This leads me to believe that the driveshaft spent most of its life in rotation perfectly straight.
I shimmed the carrier bearing mount tonight to straighten the driveshaft and to my surprise, it eliminated about 80% of the vibration. The "shims" were the thick washers that are typically on the head side of the screw that fastens mount to body, I simply placed the washer between the body and mount, lowering the driveshaft center approx. 3mm.


So my question is: what is the right way to do this? I saw a pretty nifty post from some gentlemen who used a series of twine strands, weights and then measured the length of the string in between shaft and reference string, but I don't fully understand the intricacies of what he did. I understand that Mercedes has prescribed these methods for this exact problem and I'd sacrifice my first born for that how-to.


Info on Car:
'84 300D Federal
Every bush and mount has been replaced with the proper part.
CSB was aftermarket but looked to be good quality
OEM German flex discs
OEM Trans mount
Everything torqued to spec.
Michelin's
Car was vibration free before driveline teardown, despite the shredded CSB mount.