Is the driveshaft balance bolt paired to the driveshaft, the differential or both?

[drwankel]

Over the weekend, my driveshaft center support bearing failed, and now I am hearing cowbell sounds at slow speeds.

Instead of just replacing the center support bearing, I am considering replacing the entire shaft for an aftermarket unit with replaceable u joints and a new center support bearing already installed.

The e9x m3 uses a variety of different weighted balance washers or weighted bolts depending on the year on one of the driveshaft to diff connection bolts, or possibly uses a regular bolt if everything balanced out from the factory.

When replacing the entire driveshaft, how do I determine what bolt to use? Do I use the same weighted bolt or do I need to change it?

It's not clear to me if the weighted bolt is something paired to the driveshaft, the differential, or a combination of the two. I thought I remember learning in school years ago it was paired to the driveshaft, but I'm not certain I am remembering that correctly.

My gut says that the previous weighted bolt selection is probably invalid when using a totally different driveshaft. If that is the case, how do I know which one of the three possible balance bolts to use?

[drwankel]

Well, it looks like it wont let me delete this, but I found the answer shortly after posting.

BMW says it's paired to the differential. So I just need to replace the weighted screw with the same one I already have- if I have one.

[RocketyMan]

There was a post somewhere stating this. But yeah, the different colored bolts are matched to the differential flange. It's kinda neat seeing the flange have cut-out holes for balancing.