Firstfives.org

While removing the rear subframe, I inadvertently separated the driveshaft without any marking for proper orientation.

Is there any way to sleuth out the correct orientation, or am I doomed to trial and error? The center bearing is still in place.

On the plus side, the metal under the (very crusty) diff mount looks great. No nasty surprises other than those caused by me.

528i-1981 wrote: Tue Feb 18, 2025 10:59 pm Is there any way to sleuth out the correct orientation, or am I doomed to trial and error?

I found a picture of the entire driveshaft assembled from when I replaced the CSB. The yokes on each end are aligned, so that means there are at most only three possibilities when reassembling. But if there are 10 splines, that number is not evenly divisible by 3. So there should be only one way to assemble the two halves where the yokes are truly in phase. Or am I high on hopium?

It might be hard to discern the two positions that are out of phase by less than one spline's rotation, but it's probably doable.

First of all, the forward yoke that bolts up to the Giubo has three lobes and the one at the diff has four. The picture that I had happened to show the position of balancing weights on the rear half of the shaft, so that gave me three markers. The shaft is now re-integrated so we'll see. The test will be on the road.

For posterity, the car is back on the road and the driveshaft is in balance.

Lessons learned:
1. Mark your driveshaft halves!
2. When dropping the rear subframe, be aware that the aft driveshaft yoke can hook onto the subframe and lead to driveshaft separation.
3. Keep a photo of your driveshaft assembled in its assembled configuration.

check...

I guess I had some luck left then... Still in one piece on the bench