Yes, that would cause the problem! Once corrected, with all the rest of the corrective work you've done, the car should ride like new...

Make sure you mark the two halves of the drive shaft where they join in the middle, so you can get the orientation the same. Also mark the front and rear of that bad flex disc, so you know the orientation for the replacement flex disc. I did this exact job on my now-sold '84 190D, and failed to mark the flex disc, and imagine my frustration to find that it DOES have a front and a rear and the FSM did not get any clue for a 190D with five-speed transmission.

In the end I puzzled it out looking at the pictures very carefully, but I lost at least an hour solving that one.

Flex disc didn't fix it and the original shake is back. Ugh.

I did find a crack in the seam sealer around the spring perch while under the car. Upon closer inspection (picking and peeling) I uncovered a crack that goes half ways around the spring perc. Needless to say this is my next repair in this never ending battle.

http://i336.photobucket.com/albums/n...406_221537.jpg

I know this car had a ball joint fail in the past. So I'm not saying this is a common problem. But since these cars are getting older it might be wise to add this area to the list of places to check every so often.

If this doesn't fix it then I will probably try motor mounts next then move to the rear end.

Another thread either here or different forum/list, MB owner had a high-speed vibration that turned out to be a warped wheel hub. Not easy at all to figure out, but any decent tire/wheel repair shop should be able to check all your hubs and let you know.

If the ball joint failure in the car's past was total failure (i.e. the entire wheel sub-frame left the car) resulting in the driver suddenly becoming a passenger and the car crashing, then a bent/warped hub (or two) may certainly be lurking...

Maybe try driving the car at speed on a multi-lane highway, with a pair of friends driving "wingman". The passenger in the other car should observe all four of your wheels to see if any movement can be detected, then at least you have narrowed the problem down to one or two wheels, or not a wheel problem at all but something in the drive-train, like a out-of-balance drive shaft or a really bad rear axle.

Not the previous owner but the owner before him actually kept good records. The car came with a file dating back 6years. In the paper work there is a receipt that says "urgent ball joint replacement needed before alignment." Followed by a receipt a few weeks later that reads "ball joint replacement. Complete failure!!!." Also, when I got the car the right fender well was somewhat mangled as if the hub fleww out and the strut rod hit the fender. Pretty terrifying.

I'm welding up the perch today. If that doesn't help I am going to do motor mounts, and check the hubs. I will probably replace front discs.

Before...
http://i336.photobucket.com/albums/n...414_144642.jpg

And after...
http://i336.photobucket.com/albums/n...414_171856.jpg

The driver side perch was being held on by 2 tack welds and some seam sealer. I could literally flex the perch with my bare hands. After cleaning everything up we welded up the inside of the perch and patched the outside with new metal. Inside the repair I applied weld through primer and outside 3 coats of catalyzing epoxy primer. When I have time I will redo the seam sealer and chip gaurd.

The car does feel more stable, especially over bumps. While the didn't shake on the 15mile freeway drive home, I am not convinced that my high speed shake is gone. I will still be replacing motor mounts since mine are original. I am hoping that, along with a new set of tires and a 4 wheel alignment will put this in the past.

She has fooled me before.