The Mercedes drive line is considerably more complicated than the typical driveshaft with a Hook joint at either end. It's one reason why these cars are so smooth, but complexity can bring increased repairs as components begin to degrade.

The front flex disk is the number one suspect when there is excessive "driveline slop", and any with over 60K miles is automatically suspect.

The only way to verify the condition of the front flex disk is to get the car in the air, get under it, and with the transmission in Park or first on a manual and the brake off, apply torque to the driveshaft in both direction with your hands, and, with the aid of a good flashlight, look for excess flex and cracks in the flex disks, particulary the front flex disk.

Duke