big nut at stern turns easily, both ways. ?how worried ought I be?

[SteelCruiser]

Had my 33’ steel cruiser up on the piles between tides.
Noticed the big nut at the end of the propellor shaft is loose.
Spins both ways easily, by hand.

when I turn one way, the gland packing seems to be ‘spun’ slowly out.
Since tide was coming in. I poked that packing back in, best as I could.
Motored away with the tide 15 minutes.
Sitting now on anchor.
How worried ought I be?
1. Propeller may fall off?
and / or 2. large hole appears suddenly in stern tube, sinkin* me.

have a video - link below
https://imgur.com/gallery/aCctYOs
.

[StuM]

Already asked:
https://www.cruisersforum.com/forums...ml#post3146825


There's no point in asking the same thing twice, and besides - it's against forum rules
https://www.cruisersforum.com/forums...ork&page=rules
"Do not post the same discussion more than once or in more than one forum."

[osprey877]

If your boat is like mine and most others, your prop could likely not be removed without a gear puller or at least some serious hammering, unless you've had it off recently? If the prop was loose on the shaft, you would have noticed it and mentioned it in your post, so presumably is still tight. Biggest risk of it coming loose is when you are in reverse, so don't back up until you tighten it. On the next tide, tighten and then lock it in place. There should be a hole through the nut that aligns with a hole in the shaft that you can put a split pin in, or you can drill a hole or perhaps a locking tab washer could be used. In any event, it needs to be snug and locked in place.

[AKA-None]

Castle nut is what you’re looking for

[Wotname]

The nut the OP is talking about is on his stern tube, not on his prop shaft even though he mentions the term prop shaft in the post!

The video links tells a thousand words

[Wotname]

Originally Posted by StuM

Already asked:
https://www.cruisersforum.com/forums...ml#post3146825


There's no point in asking the same thing twice, and besides - it's against forum rules
https://www.cruisersforum.com/forums...ork&page=rules
"Do not post the same discussion more than once or in more than one forum."

Yeah but..... it has a different title

[OloteleMtn]

The nut that holds on the prop is outboard; the thing you are spinning....not sure but shouldnt that be a sacrificial zinc? If it is, it should spin with the shaft, not freely. If it is not a zinc, beats me what it is for....the shaft packing is on the inside, usually.

[Captn_Black]

The zinc may have been installed between the nut and the prop, and has corroded away, resulting in the current situation. Sometimes there a a split pin installed through the threads to prevent the nut from working loose. Check to see it there is a hole where it used to be and replace it.

[Sailmonkey]

That looks like an anode to me.

But it’s hard to tell from your video, your hand is I. The way.

[osprey877]

Originally Posted by Wotname

The nut the OP is talking about is on his stern tube, not on his prop shaft even though he mentions the term prop shaft in the post!

The video links tells a thousand words

Sorry, didn’t see the video link. When the OP said it was the large nut on the end of the propeller shaft that was loose, I mistakenly thought he meant the large nut on the end of the propeller shaft.

[psneeld]

Originally Posted by Sailmonkey

That looks like an anode to me.

But it’s hard to tell from your video, your hand is I. The way.

Agree!

[a64pilot]

I am going to guess that his packing is external because there is no space internally to have a stuffing box?
It won’t sink the boat, but you may have an excessive drip now. I would at the next cycle screw the big nut down by hand until it contacts the smaller nut, then using two wrenches lock them together.
Normally that’s done inside of the boat and with water present so that the tightness can be adjusted to have just a tiny amount of a leak when the shaft is turning, but as your is external if I’m right just have to guess at the right amount.
I’m thinking the big nut has backed off and the smaller lock nut has not moved

[Bill Seal]

It looks like some "mechanic" found an extra packing gland nut when re-installing the prop shaft and couldn't figure out what to do with it.
Or maybe to avoid getting fouled with fishing line.
It doesn't seem to be moving in or out.

[Hermia II]

Unusual arrangement. If you have a stuffing box inside the boat then I would guess this nut holds a cutless bearing. The shaft has to be supported at the aft end. The most critical thing is if barnacles, or what have you, catches the propeller in revers and screwed the nut out (it will get tighter and tighter against the prop) Eventually it could perhaps pull the shaft aft long enough to make it part from the axle coupling. Your rudder would stop it sliding out, but you would be in trouble. Try locking it with Loctite 243 if there is no means of locking with a split pin, steel wire or the like.

[a64pilot]

I’m pretty sure there is a locking nut, look at the video before he puts his hand in the way, it appears to me there is a nut, but I am looking at a small IPad screen.