My 1985 300CD (135K miles) has a rythmic vibration problem that I haven't been able to solve completely. I had the original shaft removed and balanced (and the universal joint rebuilt) but that didn't help. Since then I've had two other drive shaft shops tell me that they won't even try to balance or repair the mercedes shafts because they are too difficult. I can't imagine why that would be so but thats what they said. I've also had bearings repacked, replaced engine/tranmission mounts, center driveshaft bearing, differential mount, and had the wheels balanced/checked about three times. I'm not sure what to do next.
Anyone got any suggestions?