Water Leak C320 Driveshaft

[Witbooi]

Hi. First post here. We are new Catalina 320 owners. Noticed a water leak on the driveshaft (photo included). This is new after a prop was replaced earlier this year with the boat still in the water. This is not the occasional drip. It sprays out and all over the locker when the shaft is rotating.
I’ve tightened all the clamps on the rubber boot on the shaft. It lessened the amount of water spraying, but it’s still excessive in my mind.

How would you recommend I address this issue (assuming it’s an issue)? When I putt pressure on the clamps to tighten them water enters through the boot. Is this normal? I’ve searched the forum and it’s probably because I’m new, but struggling to find an article on how this mechanism works.
I appreciate any feedback and guidance.

 

[Tally Ho]

Your shaft seal appears to be a PSS dripless shaft seal.

Here is a website with a lot of FAQs.

PYI Inc. | PSS Shaft Seal FAQ's

On this page you'll find questions and answers to some of the more common questions regarding the PSS Shaft Seal.

www.shaftseal.com

If you don’t know how old the bellows are, it may be a good idea to replace them. I would also be very careful with the water injection barb…as these have been known to fail.

Essentially, a stainless steel rotor is mounted on the shaft, and it is pressed up against a ceramic disk which is held stationary by the bellows (and the bellows keep pressure on the 2 parts).

If the ceramic disk is worn, or the SS rotor is scored or damaged, you can get a leak….
Or if the bellows are weak, you could get a leak…
Or if the bellows have a tear…you can get a leak (a very serious concern).

Greg

 

[Don S/V ILLusion]

While you are crawling around down there, you would do well to replace those barbed hose clamps with the type similar to the ones on your shaft seal.

 

[Calif. Ted]

I think that is a PSS shaft seal, only supposed to "spray" on initial installation for an hour while it seats. Halfway down the installation instructions is a troubleshooting guide and the FAQ also addresses leaks.
PYI Inc. | PSS Shaft Seal
PYI Inc. | PSS Shaft Seal FAQ's
PYI Inc. | PSS Installation Instructions

 

[Blitz]

Is the leak at all rpms?

probably worn or inadequate pressure on bellows.

Check for excess engine vibration or alignment issue.

 

[Scott T-Bird]

The spray should not happen AT ALL. The seal should not allow any water to leak through. The fact that it sprays when the shaft is rotating is a classic case where the mating surfaces are not properly aligned. One surface is still, the other surface rotates with the shaft, and when they are properly aligned and held together with pressure on the bellows to hold the surfaces together, the seal does not allow any water to spray.

You say "it" is new when the prop was changed. So the prop is new or the shaft seal is new? Both? I might suggest that you have a shaft alignment problem and the shaft is wobbling, but you don't seem to indicate that's a problem ... so the PSS installation is FUBAR. Clamping down on the bellows tighter is not going help and if you tear the bellows you are in deep shit. Is this boat really new to you and it has been doing this from the get go, or did this develop while you owned the boat? It needs to be repaired like right now and if the seller delivered in this condition, maybe the seller should be paying for the haul-out, because it isn't going to be repaired in the water.

And @Calif. Ted is right ... is this installation so new that it is breaking in? Installer should have said something if this is the case ...

 

[Tally Ho]

The spray should not happen AT ALL. The seal should not allow any water to leak through. The fact that it sprays when the shaft is rotating is a classic case where the mating surfaces are not properly aligned. One surface is still, the other surface rotates with the shaft, and when they are properly aligned and held together with pressure on the bellows to hold the surfaces together, the seal does not allow any water to spray.

You say "it" is new when the prop was changed. So the prop is new or the shaft seal is new? Both? I might suggest that you have a shaft alignment problem and the shaft is wobbling, but you don't seem to indicate that's a problem ... so the PSS installation is FUBAR. Clamping down on the bellows tighter is not going help and if you tear the bellows you are in deep shit. Is this boat really new to you and it has been doing this from the get go, or did this develop while you owned the boat? It needs to be repaired like right now and if the seller delivered in this condition, maybe the seller should be paying for the haul-out, because it isn't going to be repaired in the water.

And @Calif. Ted is right ... is this installation so new that it is breaking in? Installer should have said something if this is the case ...

I assumed he meant that the “leak” was new…

Greg

 

[Witbooi]

Thanks for all your input. I spoke with Tech support at PSS today. He’s sure that while they were banging on the shaft to install the new prop that it decompressed the bellows. His suggestion was to re-compress the bellows at 1/4” increments. I’ll try this first and if that’s not the issue I’ll start looking at the shaft. This is the shaft and seal that came with the boat. It only started leaking after the prop was installed.

 

[jssailem]

All of what is said above are possibly factors to your spray issue.

• Shaft alignment. Looking at the clamp bands in your image, the red arrow. The angle is a little different than the other 3. It could be just the angle of the image or how the band was placed. Shaft misaligned can cause wobble in the shaft seal. It can also wear out your cutlass bearing. It is adjustable at the coupler (in the area of the green arrow.) If there was banging on the prop and a new shaft was installed, the coupler needs to be carefully aligned to prevent wobble.
• When all is assembled in the boat and the boat is in the water, you need to assure the proper amount of compression is applied to the bellows. Check the spec in the install manual.
• The materials of the PSS are pretty tough. There is a mating period when they smooth them selves. The manual talks about this, identifying it as a little spray at the two surfaces (the one stationary and the other rotating). The spray should stop as the two surfaces adjust.
• If dirt, sand, silt, or something gets between the steel collar and the graphite ring it can cause a surface issue and spray. The manual describes sliding a cloth between the surfaces to wipe any foreign body away. This may solve the issue. There will be another run in period.

If it was me I’d first check the shaft alignment. You should be able to use a feeler gauge and confirm that the engine and the shaft is in alignment at the coupler without undoing anything.

If that is the issue check that you have adequate bilge pump capacity and then align the shaft.

Next I’d use a cloth to clear/clean the PSS surfaces of sand.

Then I’d deal with the compression possible issue.

When I installed my PSS the boat was hauled out. When we splashed I had to recheck everything and make some final adjustments to the compression and the alignment.

Good luck. If this is all new, call in some professional help. You get new knowledge for future issues and the problem gets solved.

 

[Scott T-Bird]

Usually, they say not to re-use the set screws. Once positioned, they are good for only one use and should be replaced if re-positioned. Perhaps I am wrong about this, but I would look into it. A safeguard against the bellows suddenly becoming "decompressed" is a shaft collar that can be secured as a back-up. I installed this on my boat because I don't know the history behind the PSS (installed before I owned the boat). This is one area that you don't want to mess around. As reliable as the PSS reportedly is, a failure can be catastrophic.

https://www.grainger.com/product/36WY56?gucid=N:N:PS:Paid:MS:CSM-2295:TVRYAD:20501231&gclid=7c1f8c8dc1a21598cfeee9ba1224503a&gclsrc=3p.ds&gclid=7c1f8c8dc1a21598cfeee9ba1224503a&gclsrc=3p.ds&msclkid=7c1f8c8dc1a21598cfeee9ba1224503a

 

[Rick486]

Contrarian view.
I owned 3 sailboats over 38 years with traditional shaft seals composed of a bronze shaft seal assembly and a lock nut. All three seals were 100% reliable, not one failure, and barely dripped a drop an hour maybe. And I never worried a second about them. Plenty other stuff to worry about.
I definitely believe in KISS.

 

[Scott T-Bird]

Contrarian view.
I owned 3 sailboats over 38 years with traditional shaft seals composed of a bronze shaft seal assembly and a lock nut. All three seals were 100% reliable, not one failure, and barely dripped a drop an hour maybe. And I never worried a second about them. Plenty other stuff to worry about.
I definitely believe in KISS.

That's great, but what does it have to do with somebody who buys a boat with PSS?

 

[Rick486]

Think it through.....

 

[Scott T-Bird]

Well, I see it as a recommendation to change it out ... but that doesn't seem to be what the poster is asking. Regardless, there is that school of thought! I might consider it when I pull the shaft some day.

 

[TimFromLI]

If you are going to try to move the collar 1/4 inch at a time. Do not reuse the set screws and unless you have done this before, do not do this in the water. I changed my pss shaft seal last year and I would not be comfortable adjusting it in the water. The bellows should be changed every 6 years. If the life is unknown and it's leaking- change it when the boat is hauled for the winter. The whole setup is not all that expensive. $300 or so for my boat. Failure of the seal can sink your boat. If you are mechanically inclined, you can do it yourself. The hardest part is getting the shaft coupling off the transmission. There's a great write up here:

Installing a PSS Shaft Seal - Marine How To