My primary mechanic (Mercedes specialist) says I can just replace the joint in the middle, no problem.
My second-opinion mechanic says I need to drop the entire drive shaft, send it in as a core trade-in, and purchase a re-manufactured shaft unit that has been balanced ($400). He says if we just do the joint, the shaft will be unbalanced, leading to more serious problems.
Flex-discs have been replaced, but there is a definite lurch when the car shifts when not under engine load. When under higher rpms and under load, the car shifts much better, much smoother.
Does anyone have experience with this? Feedback is appreciated. Jason