Packless Shaft Seals

This PSS is between 10 & 12 years old. Sometimes it sits in a little fresh water that comes in from the rain. I have noticed the deterioration of the rotor (arrow) since this summer. From the diagram on the PSS website, it looks like the rotor is going to need to be replaced if it keeps chipping away - or whatever it's doing.

Have you seen this condition before? Is it possible to replace only the rotor or is it best/mandatory to replace the entire seal assembly? Thanks.

Put it on your list

Next time the boat comes out of the water change the whole thing. it is all the same age! It is messy to try to do in the water, and you don't want it to fail because you tried to save a couple bucks. Anything thats sole job is to keep the water on the outside of the boat should be the best and perfect in condition. Or keep the insurance police current!!!

Yeah, you're right. That was a dumb question. The bellows is probably full of guck from the animals living in there anyway. It seems like a strange way for stainless to fail, being out there the open and usually dry. I see a cascade of tasks for this spring's visit to the yard. But I can check off some rare items as a result.

Tides Marine Dripless Shaft Seals?

I'm checking on a dripless shaft seal product I have never heard of.

Here's a link:
http://www.tidesmarine.com/seriesone-shaft-seals.html

Does anyone have any experience with Tides Marine products, specifically their shaft seal systems? The yard where I will do my haulout recommends these (and will install or repair them), but they won't mess with the PSS dripless. They will give me advice and look over my shoulder while I do the work, but they do not touch the PSS type. I haven't decided whether I want to do the work or not, so I'm getting an estimate for them to do the Tides Marine type.

Thanks in advance for your wisdom.

Although I'm not familiar with them, I am interested, as my PSS dripless shaft seal will need replacement in a couple of years. Do you know why your yard won't work with the PSS dripless shaft seals--they seem to have a very good reputation, with some higher quality boat builders using them on their new boats.
thanks,
Frank.

I don't recall any of the direct sources, but when I was looking at which packless shaft seal to install on our boat I found that the TidesMarine shaftseal did not have a good track record. Its failure method was nastier and seemingly more common than PYI's. Maybe its design has changed since then. Please research it carefully. I'd be interested in what your yard says, esp. as PYI is "local".

In your first picture, what is that red plate between transmission output coupling and the drive flange? Some type of vibration damper?

The red thing

jmcpeak,

That red plastic device is designed to protect the tranny, and to some extent the propeller shaft, if the prop hits something and stops suddenly. It will shear internally, at a much lower energy level than the bolts. Basically the two flanges attach on opposite sides of it instead to each other. I can't recall the make - it's in the paperwork on the boat.

As for the shaft seal, the yard I am going to use is an outfit up here at the beginning of the navigable part of the Duwamish Waterway - Delta Marine. On larger power craft they certainly could be trusted. I will probe them about their bias against PSS. It may be as simple as a dealership arrangement. I have nothing against the PYI PSS product, it has served me well. The water I find in my engine bilge is fresh - leaks in from the rain - or I may have a little fresh water system leak I haven't found yet.

The Tides product has a replaceable sealing surface - there's a video about it. But that isn't really a selling point for me on a sailing craft. It looks like the PSS stainless steel parts and the bellows will deteriorate long before the carbon seal will start to leak.

Craig, I only have experience with the pss shaft seal, and one advatage is you can turn the stainless ring end for end and have a new surface. The only issue I ever had was caused by lack of use, and a shelled critter decided to set up homesteading and his calcium like residue caused a small fog of spray when the shaft was turning. A small piece of wet/dry paper while the shaft was turning reseated everything in about 2 minutes. I think that boat still has the same seal after15 years, no problems, yet. I will put one on the 38 this summer, they are around 100bucks if I remember right, at Fisheries.
Harold & Jessie S/V Mischief Maker

When I get the thing apart I'll be able to see how it's held up and maybe get some advice from PYI about why the pitting and deterioration occurred. I haven't gotten to the price yet. I hope it's only a hundred. And I hope the shaft is ok, too. Plenty of questions as I get into this part of the boat. The feathering prop, which is working great, just needs lubrication. And I wonder if I will have to drop the rudder to do all this - or maybe just remove the prop. I will probably have them buff up the prop and put on some of that gray anti-fouling paint. I haven't had big problems with hard growth, however.

Teardown

As bad as those photos look, there wasn't really anything wrong with the PSS after all. I realized that after I had to cut the bellows (still in very good shape) to make room to back the shaft out so I could get the flange puller into the gap. The carbon seal got in the way and it's in several pieces. Going back in with the new one should be interesting. At least I won't have to grow fingers again to work the puller. The stern tube is almost 1-5/8" O.D. I saw that there were only 1-1/2" and 1-3/4" on the shelf. I imagine the smaller would be better.

The flange came off the shaft reluctantly, but it did come off. The shaft seems OK, but has to be cleaned up with emery cloth. It has a few scars. I left the prop on the shaft as it has very little play.

The cutless bearing is shot as the accompanying picture shows. If the shaft hadn't been removed it would have probably lasted a few more years.