Apologize for once again raising this much discussed subject. But after reviewing all the posts and also various recommendations from this and other forums, I'm still left with questions.
Have to replace the seal on our MKII. (Previous seal was a Lasdrop Dry Seal, which failed immediately when we launched this week. There was a backup seal on the shaft, but this leaks also. And now there is no option but either replace or renew the seals. I don't like the rather basic construction of this seal type and we are opting to change it to the PSS style.)
Have removed the coupling and seal. Now the question is: what's next. Based on the recommendations from this and other sites I won't re-use/re-install the coupling. Instead plan to use a split coupling, also based on recommendations from others. The Buck Algonquin split is the choice. The vendor site and others indicate that the shaft and coupling should be fitted and faced before re-connection to the transmission. How is this done? Do I have to remove the shaft too (including removal of rudder or cutlass bearing/prop), and have it faced at a machine shop? Is this a one-time deal? If it is done at a shop I will have to disassemble before re-installation. Will the "facing" still be good after the disassembly/reassembly?
Don't know what caused the seal failure. The boat is relatively new (2006, first launched 2008). I don't know whether the Lasdrop was original or installed later, but ring markings on the shaft would imply that there was an original stuffing box, with the seal added later. It didn't last long, although we had no problems last year (which was our first). No accidents and there are no apparent shaft problems. No leakage when stationary, but once the transmission is engaged there is considerable leakage right at the shaft. The Lasdrop is very basic, relying only on a small "rubber" contact surface with the rotating shaft. The provision of a "backup" seal already installed on the shaft tells a story - a failure is anticipated!
Hoping somebody can give me some guidance. There is a lot of information available but it can lead to confusion.
Thanks.
I would do the following:
Nick Caballero
Retired C36/375IA Mk II Technical Editor
Thank you for the reply. That procedure is clear.
Other comments are also most useful and good advice.
[quote=suslee]... The Buck Algonquin split is the choice. The vendor site and others indicate that the shaft and coupling should be fitted and faced before re-connection to the transmission. How is this done? Do I have to remove the shaft too (including removal of rudder or cutlass bearing/prop), and have it faced at a machine shop? Is this a one-time deal? If it is done at a shop I will have to disassemble before re-installation. Will the "facing" still be good after the disassembly/reassembly?...[/quote]
Having just done this over the off-season (incidental to rebuilding the shaft log tube -- https://www.catalina36.org/comment/57414#comment-57414 ), I can report to you that the fitting/facing operation by the machine shop is a one-time operation. The prop shop I went to for the work in fact ordered the BA split coupling and fitted it for me, along with the new shaft key (and checked and straightened the shaft while they were at it.
BTW, I had contemplated going to a PSS seal since I had everything disassembled, but the prop shop advised that I'd need to buy a new shaft for it to work properly, because of wear on the existing shaft (you might want to consult your prop shop on this as well). So I continued with the old-style stuffing box, but installed a new one and a new shaft log hose as well -- again, once you have all of this disassembled (a major PITA) you might as well put new parts in at this point while you have the chance.. Anyway, congrats on getting the old coupling off -- that's about 90% of the job, from what I experienced!
Matthew Chachère
s/v ¡Que Chévere!
(Formerly 1985 C36 MKI #466 tall rig fin keel M25)
2006 Catalina Morgan 440 #30.
Homeported in eastern Long Island, NY
Also did this a few years back. Rather than deal with the hassle of de-coupling/refacing/etc, I opted to just cut the old shaft with an angle grinder to remove and replaced it with a new shaft and split coupling. Catalina direct has new shafts (~$350), couplings, and will do the facing. Maybe a bit more expensive, but saved me the possible days-worth of effort trying to get the old coupler off the shaft...
Josh McElwee
Sailing from East Greenwich, RI
2000 C36 MKII, M35B, "Chinook", Hull#1900