Forum bmwbike.com

Hello. I need to take apart the drive shaft to the rear wheel but can't understand how to do it; it seems that the shaft is stacked (?) inside the flange that is mounted in front of the big rubber shock absorber, at the engines side. The cross (Kreuzgelenk) is riveted and has no bolts, there it is impossible to take it apart. So how can one dissemble this section? Am I missing something or doing something wrong? Regards and thanks in advance! Michael Steinmann.

check out this link www.bluemooncycle.com. He has info on restorations and how to information. Good Luck

The flange on all the plunger-framed models is a tight, interference press fit. You're right, there is nothing holding it on to the shaft apart from a very tight grip. As such, you can only successfully dismantle and reassemble the flange and shaft by using a press, preferably an hydraulic press.

It is important to mark where the flange is positioned on the shaft before they are parted as you will note there is no locating shoulder. The distance between the universal joint at the pinion end and the face of the flange that locates against the rubber cush drive is critical. Too short and the rubber will flop about; too long and you won't be able to fit the final drive assembly back in the frame.
The flange needs to be properly supported to avoid distortion. A narrow tool should be used to press the shaft out. This is a job for a specialist.

IMPORTANT! On NO ACCOUNT allow the mating surface between the shaft and flange to be polished, buffed or abraded in ANY WAY during refurbishment. If you do you will destroy the interference fit of the two components that provides their torsional strength. This is particularly important if you have the shaft re-plated. You have been warned!