Packing Gland Leaks Like a Siv...

[SailingChance]

I am currently cruising the Bahamas, and I'm in Eleuthera. I've been dealing with some minor engine issues and since I am pulling the engine, I thought I'd consider addressingmy packing gland.

I put new flax packing in 6 months ago, but at rest, I am getting more than 1 drip per second which is way too much. I run my bilge pump constantly. When I am at anchor for more than a day or two, and i stuff some paydoe around the the cutlass bearing to stop the drip. That being said, because I have a V drive and a centerboard, I cant get to the packing nut without pulling the engine - just take my word for it.

I considered this problem a minor inconvenience, just something to keep an eye on. But since I'm pulling my engine up to clean out the area and look for my oil leak, I thought I would address it. The packing nut is as tight as it will go. And if I shift the prop shaft aft a couple of inches, the drip stops.

This tells me 2 things, that the shaft is worn down at the packing glad AND/OR my engine is slightly out of alignment.

My eninge has stainless mounts glassed into the hull with 4 precise mounting bolts, meaning there is no wiggle room to slide it around. The coupling DOES line up with the shaft coupling. and my V drive has a universal gear that is supposedly supposed to compensate for minor misalignment.

That said, I have some playdoe for the outside of the shaft and some new goretex packing that I could put it in. The packing would be the same size. 1/4".

Is this even worth doing? Should I just deal with the drips and monitor the bilge? Is there some major issue I am not thinking of? I will be back in the stated in 2 months and can haul out then, but, should I wait? And if the shaft is worn, is there anything I can really do besided getting a new shaft?

[model 10]

You could put a longer or shorter piece of hose on the sterntube. I did this a couple of times when we still had a bronze shaft. It would show wear after not that long. I don't know about everybody else but I need to tighten up a flax packing several times before it's leaking slows down. I guess I would also switch to the other material if you could not get to it.

[a64pilot]

If you don't you'll wish you had after you get that engine back in. I like the idea of shortening the hose length, doubt I would have been smart enough to think of that myself

[Nicholson58]

Ours is a 50mm straight shaft to an external strut & cutlass. 1984 boat. I also had a leaking packing gland & also vibration at prop speeds over 500. We pulled the shaft in the fall on the hard. Cutlass was a wreck. The shaft was worn about 2 mm under in the cutlass and both worn & corrosion pitted at the packing. Calcium sea growth had ground the shaft down at the cutlass and anaerobic corrosion & wear wrecked the packing zone. Replaced the cutlass - easy.

I took the shaft to our machine shop & turned the worn areas true & clean. I sent the shaft to a plasma spray metalizer to have the under size zones built up. I then turned and polished it back to true size. Problem gone. It was mandatory to fix ours since it is an integral part of the Hundested variable pitch transmission. In your case, you might be able to get a new shaft easier.

[Cheechako]

have you had the shaft out? I'm betting a groove worn in the shaft or pitting corrosion. The corrosion can be quite bad sometimes, especially if the boat sat for some time. The SS shaft doesnt like the stale Salt water in there and corrodes fast, That roughness tears up the packing.
New engine?New shaft!
Nicholson58's pics are perfect.

[Gerrycooper56]

PTFE packing works reasonably well on scored areas as it molds to the shaft.

[model 10]

Originally Posted by Gerrycooper56

PTFE packing works reasonably well on scored areas as it molds to the shaft.

How could a packing mold to a corroded rotating shaft? As soon as it molded into a pit it would shear off when the shaft turned.

[Gerrycooper56]

I didn't see in the post that the shaft was corroded. As I said, PTFE packing works reasonably well on scored shafts.

[a64pilot]

I believe he said scored, scored means in rings, PTFE might conform better to scored rings than other packings

[model 10]

Originally Posted by a64pilot

I believe he said scored, scored means in rings, PTFE might conform better to scored rings than other packings

Perhaps but a "scored shaft is not going to be perfectly grooved so as to allow leak free operation with any kind of seal. It will be more like coarse threads. The end play of the transmission output shaft will see to that. As for packing type, one could argue that a flax packing is the best as it contains wax which melts into the groves in the shaft.

[Capt Phil]

So if you push/pull it to one side the leak stops? Bent or untrue shaft... needs to be pulled, checked for scoring and tuned, turned or replaced. Do your engine mounts allow for better alignment adjustment? Can you adjust to push/pull the shaft over to where it doesn't leak tempoarily to get you to a shop? Is your packing new or worn? Do you have the correct sized packing? Sounds like a fixible problem but may require a shaft pull to be certain and for peace of mind. Some sound suggestions on previous posts... Phil

[Terra Nova]

The shaft must be inspected and repaired as required. Make sure your're installing the packing properly, and using the right size and amount (I doubt you have installed enough turns).

[Jim Cate]

If the scoring/pitting are not serious enough to be structurally worrying you could consider using a Speed-Sleeve (not sure of the exact trade name, but like that). These are very thin sleeves that slip over a shaft in the worn area and provide a new surface for the seal (whatever type it is) to work on. Commonly used in industrial applications, not very dear and easy to install.

But the big issue is the inaccessibility of the seal. That would be a real worry to me, for no matter what type of seal you use, it can fail, and if you can't get at it...

I think that I would opt for a dripless type myself. Once installed, they typically go for a long time with zero attention.

Cheers,

Jim

[sabray]

If at rest and it's packed proper it shouldn't leek. You don't need a new stuffing box system. You tighten it up a tad. If you can't tighten it anymore and it leeks it's not packed proper or your shaft is pitted real bad. Don't think you need to change the stuffing box. Just repair what failed. Shaft or packing.


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[JPA Cate]

The OP wrote that the nut is all the way tight, and he still has the leak, so he needs to re-pack the box (and I'd use the PTFE, too, it worked great on our first "Insatiable"). Since the engine will be out, I'd remove the shaft and have a look, anyway, then decide what needs to be done. And replace the cutlass bearing, since the boat's out of the water now.