Leo,

I replaced the driveshaft in my Euro 123 with one from a US 123 and could see NO difference whatsoever between the Euro and US.

To troubleshoot your driveshaft vibration, however, I would start by ensuring that the front and rear sections were properly aligned if the splined portion was taken apart for any reason. If you are not sure, some of them have marks cast into the u-joint area in the form of a knot. I would have to dig through my literature to find the diagrams on how to align them.

Additionally, remove the driveshaft enough to flex the u-joint and see if there is a "notch" worn into the u-joint. If so, the u-joint SHOULD be replaced, but sometimes, you can change the position of the carrier ever so slightly and make the u-joint operate on a slightly different area, making the vibration go away. Do this by putting a washer between the carrier and the body at one bolt hole.

If all this fails, email Steve Brotherton (SteveBFL) at Continental Imports in Gainesville, FL. He has a source for a driveshaft shop that will rebuild it and make it smoothe as silk.

Good luck,