Josh, I am far from being an expert, but…
- I don’t think there is any issues with having very little of the shaft “free”. In my boat I have about 1/4” (free). The issue, in my mind, is not how much is left free after the assembly, but rather, how you can assemble all pieces together. - the shaft log has to be long enough that you can safely put the seal on it and secure it with two clamps. You want that seal to be as secure as possible. - there should not be any “flexing” (sideways) of the seal. The shaft should go through the middle of shaft log and should not be moving around. I might be trivialising the problem, but.. Marek 1994 C270 ”Legato” Ottawa, ON From: CnC-List On Behalf Of Josh Muckley via CnC-List Sent: 16 June, 2020 09:01 To: C&C List <cnc-list@cnc-list.com> Cc: Josh Muckley <muckl...@gmail.com> Subject: Stus-List Shortening the shaft log by cutting I've asked a few of you personally so if this is a repeat then please disregard. I'm in the process of replacing/rebuilding the drive train on my C&C 37+. In the process I'm replacing the shaft, shaft coupling, shaft seal and strut bearing. The old seal was a PSS seal and the old coupling was a standard solid coupling. I had had a R&D Marine (PYI) coupling dampener and planned to reuse. The new seal is a Last Drop II from Sailor Sam's. The new coupling is a split coupling from R&D Marine. The new seal and coupling have added length which ultimately leaves only about 1.5 inches of free shaft at most. So here comes the question. First: Any concerns with only having 1.5 inches of free shaft? I have 3. - getting the coupling dampener installed requires the couplings to be separated by not just the thickness of the dampener buy rather by the thickness of the coupling bolts. - getting the split coupling on could be complicated - with the shaft seal bottomed out on the log there is less articulation available in the seal tube. The seal uses a delrin bearing to center itself on the shaft but without room to flex the bearing will just ride harder on the shaft and can even overheat. Second: The seal engages with the shaft log by at least 4 inches. If I cut the log shorter, then I could push the seal deeper onto the log and get a bit more free shaft and room for the seal to articulate. Can any of you see any drawbacks or pitfalls to cutting the log short? Thanks, Josh Muckley S/V Sea Hawk 1989 C&C 37+ Solomons, MD
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