Stern tube * packing gland * - come loose. Sinking issue?

[SteelCruiser]

Be gentle - terminology bit uncertain.
See photos.

Transmission to the left.
Have a grease filled stern tube. ( the
White steel tube heading to the right).
Attempting to grease this, I see the clamp plate has detached. Is sitting off to the left.
I find the two x bolts sitting below, in all that dark crud.
In past days, I had adjusted the two bolts on that plate to allow the 2/3 drops per minute when running.

I cannot now push the plate back on by hand pressure. It will not go 'back into the shaft'. I start to dig around, pulling out crud.

Then stop and think.
Hold up.
If sea water starts pouring in, what is my plan.

Suggestions. Comments welcomed.

[darylat8750]

Stopping to develop a plan is smart. You have a common packing gland. You need to get the right sized packing material. Subtract the diameter of the shaft from the inside diameter of the outer tube. Divide difference by 2 for the packing size. Changing this is easier out of the water but very doable in water. Check bilge pump before beginning. Clean out ALL the old packing material. When you get some of the packing out water will be coming in. Bilge pump should keep with the flow. If it doesn't you can slow it way down with a rag and a plastic bag rapped around the shaft. A drywall screw and a pair of pliers will get you started. Just screw it into the material then pull it out. Keep at it until you finish up with something like dental picks. Get it very clean and polish shaft with emory cloth. Replace the packing material following the directions. If you have a friend that has done this before it becomes very easy.

[senormechanico]

darylat8750 is correct.
It's doable in the water (I have switched out a dripless seal bellows at anchor) but if you are new at this kind of thing I would get someone who is experienced at this to do it. Either that, or get the boat hauled.
The possibility of disaster is real.

[FSMike]

Steel - It's always helpful to post your location and a description of your boat by your name/avatar etc.
My first thought was to tell you to be ready to dive in the water with any of various materials to stop a big influx of water, but it occurred to me that you might not like that if you were anchored in Alaska.

Hard to tell from the pics, but it appears that your shaft is not properly aligned with the stern tube, which makes it difficult/impossible to reconnect your stuffing box flange into your stern tube/stuffing box. Is the shaft off center in the stern tube opening? If so, that's probably the case.

Curing this usually involves disconnecting the two halves of the transmission flanges, centering the shaft in the middle of the tube, then getting the transmission flanges to match up. This is done by moving the engine by way of adjusting the engine mounts. Final adjustment involves using feeler gauges between the two transmission flanges. It's done this way because it's simpler than trying to relocate the stern tube.
Aren't you glad you asked lol?

It's not nuclear science but it would be VERY advisable to have expert assistance if you're going to do this in the water.

Hopefully, somebody will come along and tell you that fsmike is an idiot and all you have to do is add 2+2 and get 4.
Maybe.
Good luck.

[GrowleyMonster]

Is your stern tube solid? Is there any flex? On some boats the stuffing box is mounted using a piece of heavy reinforced hose to interface between hard stuffing box and hard stern tube or shaft log as it is sometimes called. Anyway if it is set up to flex, try picking up slightly on it or pushing down slightly. Also there may be enough slop in the transmission bearings and seal to enable the shaft end to move a few thousandths, possibly enough to get it back together. If it ran okay before, it will run okay now, and shouldn't be in critical immediate need of engine realignment. YMMV of course. Knock on wood.

The packing... do you know how old it is? Could be that the packing has disintegrated or shifted and is forcing the shaft up or aside so that the shaft is not concentric with the body of the stuffing box and the gland is not perfectly aligned with it.

Repacking a stuffing box is routinely done in the water. Water will enter the boat but its not like 1000psi or anything. The stuffing box is actually close enough to the level of the water surface that there isn't all that much pressure pushing the water in. I even changed my prop shaft in the water, not that I recommend doing it that way or anything. Got tired of the local yard diddling around and me waiting for haulout so I did all the work I needed done right there in my slip, including changing out my bendy twisty worn and eaten bronze shaft for a bright shiney new SS one. Pulled the prop, hammered off the semi disintegrated zincs, climbed back into the boat, pulled the shaft in (had to move motor and thrust bearing first) to the boat, and quickly stuffed the new shaft down the empty hole. Wa La. Went back over the side, stuck the end of the shaft through strut and Cutless bearing, put the prop and some new zincs back on, got out of the water, made a celebration sized oldfashioned, and bragged to everyone about what I just did. I moved fast and took maybe a gallon of water, tops.

Anyway back to packing the stuffing box, if some calamity emerges you can always stuff rags in around the shaft with a screwdriver. Been there, done that. It will hold until you get things sorted out. Be prepared. Cut your rings of packing ahead of time. Have at least 3 or 4 rings ready to go. Clean up your bolts and get some neverseize or some other antisieze compound. I like to drill a tiny hole in nuts or bolt heads for a bit of safety wire so it can't back out on its own. The wire breaks easily when you need to tighten up in the future.

If you have a more experienced neighbor you can trust on this, see if you can get him to stand by and advise as you work. But I suspect when you have pulled all the old packing, the gland will fit in there nicely, and then with fresh packing it will fit snugly but it will fit. Once it is started in all the way around and you have your bolts started, bobs yer uncle. Tighten evenly until you get only a very occasional drip seeping in with the prop stopped, and three or four drips a minute when it is turning at idle. A little bit more is okay, even. The goal is to prevent unattended flooding but allow seawater to lubricate and cool the packing. Overtighten at your peril. Lockwire or locknut everything. As you can see though, if it backs apart it is not a gauranteed marine calamity. Just a possible one. With good pumps on auto and a bilge alarm that you can trust, just checking your bilge a couple times a watch (you do that, right?) will keep you floating as far as the stuffing box is concerned.