I like your style Jack!!!! Practice on an expendable commodity!!!

My guess is that you will need an impact wrench to apply the force in the needed manner. The short, sharp, impacts that the impact wrench applies will tend to loosen the nut rather than turn the shaft. A bar with two holes drilled in it to match adjacent bolts in the flange coulds be attached with spacers to clear the back side of the flange to help limit turning of the output shaft. Along enough bar could be hand held or let lay o nthe bench as you hammer way with the impact.

You are, definitely, well advised to make sure the tranny is out of gear to prevent impact damage to sliders and such.

I think Volvo had a special spanner type tool for this task. I haven't personally done this on a M40 or M41, but have done similar work on third members. Any other comments are surely welcomed!!

Thanks for the drive shaft data!!!

Mike