@Evil Daddy, I pulled my drive train out to investigate some fine cracks in the propeller shaft. My coupling was different than yours, but a bear to get off none the less. As others have said, the shaft is probably toast…I know mine was. I took the time and bloody knuckles to get my coupling off, but in the end, replaced the shaft anyway. Could have saved a lot of time (and blood) had I just cut the shaft from the start.
If you do try to remove the coupling, as
@kloudie1 says, remove those screws or bolts around the perimeter of the coupling and see if that helps. I have not seen one like that before.
You will need to determine if your rudder has to be removed to replace your shaft…in my case on my O’Day 322, I was able to push the cutlass bearing out of the strut, remove the stuffing box, and get a little wiggle room to get the shaft past the rudder…took a little paint off, but better than dropping the rudder.
I went back with a new SS shaft, and a solid coupling. A year later, I replaced my original stuffing box with a Volvo Penta dripless seal…very simple solution. The one thing I would do differently is to use a split coupling for ease of removal when necessary.
Here are a few videos that may be of interest…
Volvo Penta Shaft Seal Install
Good luck,
Greg