Well, after having the drive shaft out twice it is done, and all the vibration is gone.
Here is the steps to remove the front and rear flex joint and realign if you happen to remove it without marking it properly....save the labor mark it its not a chevy U joint axle!!!!!!!

The car:
Mercedes benz 1990 300sel (126) Gas
Miles: 173,000
Engine: 6 cylinder 3.0
Maintance records very spotty but a very sweet car

Problems and symptomology:
1: Clunking and vibration from the area around the shifter. Very noticable harmonic vibration at speed...between 20 and 60 miles per hour.
2: Drive shaft moves up and down and all around 3/4 to a inch and the flex joint does not move...it's toast.
The cure:
1: If you are going to take the drive shaft out do it once the right way..replace the support bearing and front flex joint and you are set for many miles of driving. The rear is usually good for the life of the car...generaly...how I know this? because I went to junk yard....(thirty cars 124-126 and other assorted models and years and all the rear flexs were intact and in good shape, the fronts were all rounded out and basicly seriously trashed), but check it anyway.
Removal procedure:
1: Take the bolts (10 or 12 /10 MM) off the cover that hides the center support bearing. move it back about a 1/4 inch and it will drop a couple inches.
2: Remove the bolts holding the center support I used a foot long extention and a swivel socket to reach under the cover. (2 also 10 mm)
3: (Alighn and mark driveshaft) if you dont put the car in neutral and turn drive shaft untill the three tabs (drive shaft mounting points to flex) make a Y either two on top one down or the reverse on reassmbly but front and back flex mounts must both make a Y the same way up or down.
4: Remove the two tranny mount bolts. 13 mm I think...
5: Remove all the bolts on the front flex.....turn the shaft to ease access.
6: Remove the rear flex bolts and pry the rear flex towards the front (stay on the metal don't pry on the rubber) move it pry it and turn it untill the drive shaft drops off the small imput shaft.
7: Remove the front flex bolts just like the front but pry from the back to the front and the flex will fall out.
8: Pull the drive shaft out the rear ( it may come apart into two pieces).
9: Take the potion with the center support to a shop and have the support bearing and cover replaced. For me it was easier than trying to fight with it, and it only cost $20.00 to have it done right.
10: In the 15 minutes it takes for the shaft bearing to come back you can drink a beer or read your favorite Mercedes Benz porno or whatever.

Reassembly:

1: Alighn the two halves on the ground under car and make shure everything is in order look close for proper alignment.
2: Split the shaft in half and snake front half it into the front, but leave room for the flex.
3: Mount the front flex to the output shaft on the tranny.
4: Mount the front shaft to the flex, keeping the Y either up or down and or your marks in line.
5: Snake the rear half into the back half keepng everything in line.
6: Pry the back half of the shaft towards the front untill it clears imput shaft on the differential.
7: If you replaced the rear flex mount it on the shaft first if not just keep it in line and bolt it up,but keep the bolts alittle loose.
8: Use the flex socket and foot long extention, pry down on the cover and replace support bearing bolts.
9: Tighten all the rear flex bolts and double and triple check your work.
10: Replace all the cover bolts.

11: Take it for a ride and check for vibration. I checked it for about 3 min at all the speeds up to the " Legal Limit"