Shaft Seal (almost a fail)

[Scott T-Bird]

I was prepping our boat for a sail to Cape May next week and found this at the shaft seal. I don't know how long it has been like this but it was enough for me to re-think our trip. Luckily, it will be replaced on Tuesday so we should be GTG. BTW, doesn't it look like the bellows is way over-compressed? The original owner installed this and I don't know how long ago. Accordingly, it had been on my mind to replace it - but I should have done it no later than last winter. This is going to cost me a haul out. I might have taken the opportunity to replace the motor mounts at the same time if I had only done it in the winter, but I don't want an extended haul out now.

No leaking to even set off a preliminary alarm!

 

[kappykaplan]

Good catch! The bellows do look over compressed.

 

[dlochner]

The replacement can be done with the boat in the water if the bilge pump is running. I had ours replaced a few months ago with the boat in the water. Saved a haul out. Personally I would not have done it in the water, the mechanic said "No Problem."

 

[JamesG161]

The replacement can be done with the boat in the water if the bilge pump is running

Never do that in the water. Too many things, unexpected, can happen and sink your boat.
Jim..

 

[Charles Erwin]

In the water change will work if 1 you get the coupler off and 2 can move the shaft back enough so the coupler comes completely off and the new bellows can be slid on.

 

[jssailem]

Good to inspect the boat before a serious cruise.

 

[Blitz]

In the water change will work if 1 you get the coupler off and 2 can move the shaft back enough so the coupler comes completely off and the new bellows can be slid on.

Agreed, if you shaft zinc is placed only a inch or less from the strut you should consider diving to remove it before to allow you to be able to move the shaft back enough.

 

[Captain Larry-DH]

I would spend the money for a short haul. It’s a lot safer - and a short haul is cheaper because they don’t have to block it. If you haul just before their lunch hour you can get it done while hanging in the slings. They can drop you back in after lunch.
Notes - PSS seals use stacked set screws to hold the shaft collar, so the top one must be completely removed to loosen the bottom one that grips the shaft.
- Check your shaft seals stainless mating collar surface for smoothness - the carbon side can cause electrolytic pitting in the stainless collar. If the steel is pitted, flip it around and use the side that was facing away. Check the carbon side for even wear. You can order those as spares separately, and get some O-rings while you’re at it so you’ll have it all in your spares. (Might be better to just replace the entire assembly while you’re at it. Call PSS to price it vs. the parts.)
- Use dish soap as a lube to slide the collar. Or Superlube PFTE synthetic grease. Do NOT use petroleum grease, which might degrade the internal rubber o-rings or the bellows.
- Don’t forget to “burp” the seal after your boat goes back in, to wet the mating surfaces. You should always do that with a PSS seal.
Separate job - Check your engine alignment after you go back in. Maybe it’s just the bellows but it looks in your photo like the two sides don’t quite line up.
Edit - It might not be overcompressed. You can safely check that while in the water.

 

[Scott T-Bird]

I'm replacing the entire assembly. The price differential between replacement parts and new assembly is not significant enough to me. Besides, I really don't know how long it has been since replacement. I think alignment is fine and the bellows alignment is misleading. I do have plenty of room to slide the shaft back without removing anything under water. If I was experienced replacing these things, I could consider grounding the boat on the other side of the bay on sand at low tide. Our tidal range is just half foot and I'd bet it could rest comfortably on the wing keel while the work was done. But the travel lift is already scheduled and they will do the work while it is in the slings. I would like to clean up the coupler by grinding off the rust and re-painting. Perhaps I can get that done while the mechanics are installing the shaft seal.

 

[dmax]

When I installed a PSS and compressed the bellows as specified (3/4"), it looked pretty much like yours, the ribs were touching. If you're replacing everything, maybe consider switching to a Volvo shaft seal - people really like them and they don't have bellows that need to be replaced every 6 years. I didn't know about them at the time but would've gone that route.

 

[duck21]

FWIW, We just did the Volvo shaft seal as a part of a prop shaft/coupling/bearing refresh. We've only taken it out once but so far I'm happy with the change.

That said, you may already have hardware for the PSS, so it may be a moot point.

Doug

When I installed a PSS and compressed the bellows as specified (3/4"), it looked pretty much like yours, the ribs were touching. If you're replacing everything, maybe consider switching to a Volvo shaft seal - people really like them and they don't have bellows that need to be replaced every 6 years. I didn't know about them at the time but would've gone that route.

 

[BigEasy]

Another advocate for the Volvo seal or Radice seal. I replaced my Volvo seal at 18 years; still looked good & didn’t leak a drop. No springs, set screws, couplings, carbon interfaces. Can be had for less than $150. Recommended replacement cycle is 10 years. Very simple & maintenance free. Check it out; you’ll like it.

 

[Captain Larry-DH]

I would like to clean up the coupler by grinding off the rust and re-painting.

Caution: Do not do ANY grinding to the face of the coupling that mates with the engine. That must be done by a qualified machinist on a lathe while the coupling is mounted to the shaft, after he verifies that the shaft is straight and runout is true within .0002”. Otherwise it will not be “true” to the shaft and it could introduce shaft-whip (and associated vibration). You won’t have time to do this while the boat hangs in the slings during a short haul-out.
Edit: Also, if you haven’t pulled your prop shaft recently and the coupling is badly rusted you might find it very difficult to remove.
2nd edit: Painting the coupling might also make it difficult to re-seat the shaft. And the paint must be completely cured before putting it back in. IDK how you would accomplish that that during a short haul-out. Maybe it would be better to just coat it with lanolin anti-seize anti-rust and call it a day.

 

[Morgan donor]

PYI (lawyers) say you should change your bellows every 6 years. Mine was over 10 when I replaced it. I'd bet yours was pushing 20y.o. any idea how long it had been in service?

 

[Scott NIelsen]

Another option is the LASDROP seal. I replaced my PSS one at my last haul out and won't be messing with it again until the next haul out and plan to us the LASROP at that time. Just something to think about for next time.

 

[Charles Erwin]

Please tell everyone how things went - that way you get to do it and the rest of us can applaud your success or benefit from a less satisfactory result. Personally I am pulling for success.

 

[Scott T-Bird]

So far so good. Yesterday the boat was put in the slings during the morning and in-between the afternoon downpours we slid the shaft out. After loosening the split coupling, the shaft came out pretty easily with minimal tapping. I'm only guessing, but I believe the previous owner installed this shaft seal about 10 to 15 years ago. I think he told me it was the second one installed on the boat.

The coupling did not have to be removed at the flange with the engine mount so I just scraped and cleaned off the rust on the outer surfaces as best I could and replaced the 4 bolts one by one to avoid altering the mating surfaces in any way. I also replaced the 2 bolts that secure the shaft and cleaned and oiled the set screw.

We had already ordered the PSS seal before I made this post and we are still waiting on delivery, expected today. I would have considered an alternate product, but maybe next time. We have pouring rain for most of today in Lanoka Harbor so I'm not sure if it will be installed today. It's not a problem inside the boat, but nobody wants to be around with thunder and lightning in the picture. Also, rainwater just runs off the hull right underneath where the shaft projects so nobody wants to be under the boat in the pouring rain!

We are at a small sailing-only marina with barely any haul-out needs at this time of year, so they are happy to leave me in the slings until this gets done. They certainly aren't hauling anybody out in the rain with threat of lightning.

 

[Rick D]

So far so good. Yesterday the boat was put in the slings during the morning and in-between the afternoon downpours we slid the shaft out. After loosening the split coupling, the shaft came out pretty easily with minimal tapping. I'm only guessing, but I believe the previous owner installed this shaft seal about 10 to 15 years ago. I think he told me it was the second one installed on the boat.

The coupling did not have to be removed at the flange with the engine mount so I just scraped and cleaned off the rust on the outer surfaces as best I could and replaced the 4 bolts one by one to avoid altering the mating surfaces in any way. I also replaced the 2 bolts that secure the shaft and cleaned and oiled the set screw.

We had already ordered the PSS seal before I made this post and we are still waiting on delivery, expected today. I would have considered an alternate product, but maybe next time. We have pouring rain for most of today in Lanoka Harbor so I'm not sure if it will be installed today. It's not a problem inside the boat, but nobody wants to be around with thunder and lightning in the picture. Also, rainwater just runs off the hull right underneath where the shaft projects so nobody wants to be under the boat in the pouring rain!

We are at a small sailing-only marina with barely any haul-out needs at this time of year, so they are happy to leave me in the slings until this gets done. They certainly aren't hauling anybody out in the rain with threat of lightning.

FYI, I have had my PSS for 30 years on our 40.5 and had one on a Vision 32 before. I changed the bellows on the 40.5 after 15 years just as PM. At 25 years, I replaced the entire unit since it was 25 years old and why not? BTW, I had them delete the water injection since it isn't needed for sailboats. They just put a plug in it. Works fine. Just have to remember to burp it at launch.

 

[Scott T-Bird]

Our boat is back in the slip & all is well! The marina owner had been telling me all along that he expected that the shaft would need to be cut out and replaced because it would be bonded to the coupling. Somebody with a different opinion said it looked like no problem. I made it a point to be present while it was removed because I needed to be sure that a legitimate effort was going to be made. The marina owner himself did the work and had no problem separating the shaft from the coupling. I just said "thank you very much ... good work!"

 

[BigEasy]

I made it a point to be present while it was removed because I needed to be sure that a legitimate effort was going to be made. The marina owner himself did the work and had no problem separating the shaft from the coupling. I just said "thank you very much ... good work!"

Sign of an experienced boat owner; be present to ensure that repair is being correctly! Happy to hear that everything went well & you're back in water. Hopefully you can take that cruise to Cape May after all.