Thanks Bill, I certainly feel like a Gomer sometimes at 32. I only really picked up a wrench in my late 20s so I am still learning a lot.

I just happened to replace the carrier bearing on my other w123, because it was shot. The symptoms were certainly different than what I’m experiencing on this car. Further, when I had the driveshaft out I inspected the bearing closely and it looked very good. Mercedes part too, so I didn’t want to replace it.

I don’t think the transmission is the cause, because those guys are seasoned professionals and they tested the transmission before shipping to me.

I am thinking driveshaft. One question: if one of the flex discs isn’t completely seated into the yoke of the transmission, would that cause vibration? I recall seeing that one of my new discs didn’t seat completely flush, there was a slight gap. I didn’t think anything of it, because that gap is front/back and I didn’t think it would cause a driveshaft imbalance.

Bill, you said that 2 cycles per second is typical driveshaft frequency, how can that be? It’s certainly spinning much faster than that. Just curious what makes you say that.

Thanks!