Help with leaking prop shaft seal

[Jerry Woodward]

I have a dripless shaft seal (not sure of the brand, but it looks similar to the Elite dripless shaft seal.

It is dripping water slowly, but I had about a gallon of salt water in the bilge after about 8 hrs of motoring. It is not leaking when the engine is off, but I noticed it started dripping when the engine is running but not in gear, i.e. the shaft was not turning. I believe the vibration of the engine running is enough to allow water to come in around the hose that is clamped to the tranny side of the coupler. No water is leaking around the clear tube coming out of the top.

I think the hose and clamps need replacing, but I would need to remove the shaft to do this right? The clamps seem is decent shape and tight and there is no obvious splitting or deterioration of the hose.

Any thoughts?

[jkishel]

I assume the forward hose clamps on the bellows are clear of the hull so the bellows is free to expand. Often when a PSS leaks when the shaft is turning the bellows needs to be compressed a bit (1/8 inch or so). Loosen the set screws (there should be two set screws in each hole), move the ring aft a bit and retighten the set screws. It looks like there is a donut zinc on the shaft as a safety measure, move it aft too. Run in gear to check for leaks and move aft a bit more if still leaking. When leak is eliminated replace set screws with new ones, they shouldn’t be reused.

When a PSS leaks at rest it often means that there is some debris between the disk and the ring. Compress the bellows by hand and run a rag between the disk and the ring.

The bellows should be replaced every six years or so. This needs to be done with the boat out of the water.

[Rumrace]

Brilliant Thank JKishel

[andrzej0nl1ne]

Yours looks like a lasdroop shaft seal, not a pss/pyi as described by prior post. If correct, they work differently.

[tkeithlu]

That cheap vinyl hose feeding the shaft seal could sink your boat for you. I recommend that you exchange it for some reinforced fuel hose.

[jkishel]

Originally Posted by andrzej0nl1ne

Yours looks like a lasdroop shaft seal, not a pss/pyi as described by prior post. If correct, they work differently.

Right, that does look like a Lasdrop, suggest you call Lasdrop and have them walk you through the adjustment process.

[adjo]

It may be my eyes but I see the shaft and the stern tube as being slightly misaligned.
Are the engine mounts all good? Excessive movement of the motor can lead to leaks at the seal.

[Jake Tanley]

Not sure if the manufacturer matters (PYI/PSS vs Lasdrop), but after about 10 years in salt water, our PYI shaft seal developed a small drip at the end of that season. I followed their instructions to use 600 grit wet/dry sandpaper to clear between the rotor and seal and it quickly corrected the issue. Reference:


https://www.shaftseal.com/pss-faq.html#1


Good luck and please post your results for others.

[boatpoker]

Originally Posted by jkishel

Loosen the set screws (there should be two set screws in each hole), move the ring aft a bit and retighten the set screws..

Those allen set screws are single use.

[boatpoker]

Originally Posted by Jake Tanley

Not sure if the manufacturer matters (PYI/PSS vs Lasdrop), but after about 10 years in salt water, our PYI shaft seal developed a small drip at the end of that season. I followed their instructions to use 600 grit wet/dry sandpaper to clear between the rotor and seal and it quickly corrected the issue. Reference:


https://www.shaftseal.com/pss-faq.html#1


Good luck and please post your results for others.

Lasdrop suggests cleaning the faces with some liquid abrasive cleaner like VIM poured in the water lube tube.

[SteveSadler]

It might help to grease the seal as is required maintenance

[DIJ]

Originally Posted by boatpoker

Those allen set screws are single use.

You didn’t read the instruction in full then?

[boatpoker]

Originally Posted by SteveSadler

It might help to grease the seal as is required maintenance

No grease mentioned in the Lasdrop instructions.

[boatpoker]

Originally Posted by DIJ

You didn’t read the instruction in full then?

Actally I did, That is Lasdrops advice.

[SVRealityCheck]

When you say "the hose that is clamped to the tranny side of the coupler", are you talking about the coupler that mates your shaft to the transmission? Is the leak coming from a hose clamped to your engine, or from the dripless seal?

When you fire up the diesel, the engine delivers water to your seal by way of that clear hose going into the top of it. If either end of that hose is leaking, you would probably be able to deal with that without bothering with the shaft.