That is a pretty standard set up. The tube is held in place by the stuffing box housing screwed onto the tube and attached to the little bulkhead with the 2 locking screws (or they might be bolts with nuts on the aft face - difficult to tell from the photo). Exactly the same as the aft end where the tube is located by the bearing housing screwed on and locked to the hull.
I am still puzzled by why you want to remove the tube, but if you do then the procedure is to undo the inner and outer bearing housings and pull the tube out. This will of course break the watertight seal where the tube goes through the deadwood in the hull. Often the aft end is glassed in so it does not leak and is permanently fixed in place. However the fact that you can turn the tube suggests it is sealed with a flexible sealant at the aft end which has probably failed.
This will give you a good idea of how it works
sillette.co.uk/catalogue.pdf#page=4
To revisit this; the Sillette catalogue linked to above lists prop nuts like this alongside anodes which are secured using the tapped hole in the end; also listed are tab washers clearly intended to secure the nut once tightened.Thanks!
- The tapered prop nut came off rather easily and doesn't have a pin or anything to keep it in place. It seems to have a small threaded opening on the point of its tapered end. Should something be in there?
Crisp
View attachment 113073
A perfect illustrationI don't see any glassing here, although only the OP can definitively state what the boat has. At the risk of making assumptions; there are 4 paths for water ingress, hull/cutlass bearing housing interface(green arrow), the threaded joints(red arrows) and the stern gland itself(blue arrow). Having disturbed whatever mastic/sealant there is on the forward threaded joint it seems short-sighted to not remove, clean and apply fresh sealant to the joint while the rest of the assembly is apart.
View attachment 113828
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