Change a Dripless Shaft Seal while in the Water?

[bluepearl54]

Dive under the boat and stuff a towel in the stern tube..!

[argonauta1]

Well I hope it worked out.

We were always able to do it in conjunction with a haul out except for one instance when it leaked post splash and had to haul again.

Our Volvo shaft seal was always a major pain as we always had to drop the rudder to get the shaft (sans prop) by it without stressing either the rudder and/or the shaft. Beneteau 440. Eventually, we found the shaft was slightly out of true by a mil or two which we assume contributed to the more than usual need for replacement. No doubt this anomaly had arisen from previous attempts to get the shaft by the rudder.

Once we had a yard do a machine "straightening" the need for replacement was much reduced. What with the need to drop the rudder, we never contemplated doing an in-water or 'on the beach" replacement! Lots of opportunities for rudder bearing inspections though!

[leehaefele]

I have changed these on a Leopard 38 catamaran several times, I have also changed the shaft 2X which includes removal of the cutlass bearing and shaft together. The seal is the easiest, you need to know that you can slide the shaft back about 4 inches, (prop and rudder could interfere) and the hard part is likely removing the shaft coupling. Once the coupling is off, sliding the old seal off and the new on is a 1 minute or less job, and only a few cups of water comes in as the cutlass bearing is normally quite tight. Follow Volvo directions and use the plastic protector when sliding over the splines. If you are scared of a large water flow, do a test by sliding your existing seal off for a minute. Want to use your old seal longer? Add Grease, and gently tighten a hose clamp on the last inch of the seal. I buy the seals from marinepartssource.com. Adding folding props greatly increased seal life.

[rgleason]

When my stuffing box leaks, I just tighten it, by cramming myself over the engine or going upside down in the port locker. Why would I want to install a PSS Seal? What advantage would that be if I have to change it while in the water? That would be near impossible on this boat. At least I can fix the stuffing box, and the teflon packing repair parts are very small and inexpensive.

How long do PSS seals last? What are the advantages?

[sv Stella Maris]

Originally Posted by markxengineerin

“I doubt there has ever been a boat that sank because someone tried to replace a shaft seal while still in the water.

My catamaran also has strut-supported cutlas bearings. My PSS shaft seals when off would allow more than 20 gallon per minute, including blowing all work tools and my engine away, hehe. Not to mention salt water everywhere in my engine compartment.

Great work OP !!!!

[captmikem]

I changed mine a couple of months ago, (38 ft boat). I thought I would have a large influx of water but it was light and not a problem. Hardest part was getting the end of the shaft coupler off the shaft. Really it was not a problem changing it in the water. You do need to make sure your shaft will slide aft far enough to get the gear on.

Here are before and after shots.

M

[carstenb]

Originally Posted by captmikem

I changed mine a couple of months ago, (38 ft boat). I thought I would have a large influx of water but it was light and not a problem. Hardest part was getting the end of the shaft coupler off the shaft. Really it was not a problem changing it in the water. You do need to make sure your shaft will slide aft far enough to get the gear on.

Here are before and after shots.

M

I use a steering wheel puller to pull the coupling. I bought it at an autoparts store for 10 bucks. Works like a charm

[rgleason]

Originally Posted by captmikem

I changed mine a couple of months ago, (38 ft boat). I thought I would have a large influx of water but it was light and not a problem. Hardest part was getting the end of the shaft coupler off the shaft. Really it was not a problem changing it in the water. You do need to make sure your shaft will slide aft far enough to get the gear on.

Here are before and after shots.

M

Why did you do it?

[captmikem]

Originally Posted by rgleason

Why did you do it?

Here is why. Bellows was starting to seperate:

[cram]

Maybe they've sunk???

[CaptainMarkS]

Well done, Carsten! Nice to see the crocs didn’t get you. We were slightly concerned when you told us what your intentions were while we were neighbors, but Banana Bay seemed an okay spot.

I wonder, is greasing the shaft seal a good idea? I’m guessing they’re made of rubber or neoprene. Petroleum products interact with rubber and cause it to become brittle (which is why one never greases impellers, for example), which could exacerbate leaking over time.

Mark

[malbert73]

Any updates? I can’t imagine it’s that tough. Yes a decent amount of water will be coming in but it’s a stable situation provided you have room to work on it

[carstenb]

Originally Posted by CaptainMarkS

Well done, Carsten! Nice to see the crocs didn’t get you. We were slightly concerned when you told us what your intentions were while we were neighbors, but Banana Bay seemed an okay spot.

I wonder, is greasing the shaft seal a good idea? I’m guessing they’re made of rubber or neoprene. Petroleum products interact with rubber and cause it to become brittle (which is why one never greases impellers, for example), which could exacerbate leaking over time.

Mark

Mark

Volvo expressly says to grease the seal. Indeed the instructions say to regrease every couple of hundred hours.

I don’t claim to knowmuch about interaction of grease and rubber ( is it npr or some other type of rubber?). But if volvo says grease then i guess it it better to grease

[carstenb]

Originally Posted by malbert73

Any updates? I can’t imagine it’s that tough. Yes a decent amount of water will be coming in but it’s a stable situation provided you have room to work on it

If you look at the videos I posted you can see that the new seal was dry when we sea tested it. Since then we have sailed about 300nm to Panama City and now through the canal. No leaks.

so life is good again

[cram]

Originally Posted by cram

Maybe they've sunk???

Apologies, can't delete.... my browser was only showing page 1 and not 2/3..... great work! I feel a little more comfortable doing mine, although I might use a tidal grid (which turns into a 16 hr day.....)