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Changing prop shaft gland packing
I have a port prop shaft packing gland that I never touched for 2 years since I bought the boat (1978 53MY, 2" shafts), and it never leaked a drop except when the boat was splashed after 5 months in winter storage. This spring, I noticed that it wobbles when the shaft turns and it's a little off center. It still doesn't drip. I know it's the packing gland wobbling because I put a gauge stick against the shaft and it's running true. There must be a foreign object or a wad of packing material going around inside as the shaft turns. I guess I should'a thought about the gland when it DIDN'T drip, because it's probably overheated from being too tight. I hope it didn't score the shaft. When I run it at 2200 RPM, it warms up to the touch while the starboard packing gland stays cool.
So do you need to haul the boat to repack one of these? It's a 2 piece set of collars that fit one inside the other and it's adjusted by threaded bolts on 2 sides of the gland with nuts and locking nuts to squeeze the forward collar into the packing material held in the aft collar. I'd like to save the $ and do it in the water, but I've never done one. I've read the threads about rudder packing: having the right material on hand in advance, using a dentist's pick to pull the old material out, overlapping diagonal cuts in the material, etc.
I assume you just unscrew the nuts, pull off the forward collar, pick out the old stuff and reinsert the new packing material in layers, but it seems like the water pressure coming in would be pushing the new stuff out before you can get it pushed in properly.
And I'd rather not sink the boat.
Any actual experiences with this type of packing gland would be appreciated.
Thanks,
Doug
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Re: Changing prop shaft gland packing
Doug,
Two years ago I had my mechanic change the packing in my 48 yachtfish. I had never done it before so I wanted to see how it was done with the boat in the water. I too have two inch shafts with the same collar setup you have.
Basically it looked pretty easy. As you noted he pulled the inner collar out and used a pick to pull out what was left of the old packing material. Surprisingly little water came in without the packing. It was a steady flow, but nothing that would make me think that it was a problem. Instead of cutting the packing at each round with a diagonal cut, he wrapped the packing around the shaft about three winds, cut it and shoved it in. He then did a second wrapping of about three rounds and shoved that in in front of the first wrapping. He put the collar in pretty loosly, just enough to hold it in, had me fire up the engines and then put them in gear at idle while he adjusted the packing so that it dripped about three times a minute.
Hope this helps.
Dwayne
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Re: Changing prop shaft gland packing
The last shaft that I packed was years ago on a 57' Chris Craft Constellation. As stated, it was a steady flow of water, but really quite easy after you get over the initial shock of having water running into the bilge. Good luck. :p
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Re: Changing prop shaft gland packing
No big deal.
Go get the GFO packing material. Expensive but worth every dime; mine is 4 years old and doesn't leak. 'Nuff said.
Yes, it can be done in the water. I've done both the mains and rudder stocks wet. Water comes in, but its not a big deal. Just make sure you have the correct packing BEFORE you start! :D
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Re: Changing prop shaft gland packing
Thanks for the replies, guys.
Is there a "size" of packing material I should get? And what does GFO stand for?
Doug
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Re: Changing prop shaft gland packing
GFO is a goretex material - its good stuff. That's what its called "GFO" packing.
My shafts use 1/2" - both the rudders and screws.
Find it here, if you can't get it locally.
http://www.e-marine-inc.com/products...g/packing.html
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Re: Changing prop shaft gland packing
Thanks,
I'll let y'all know how it goes. :)
Doug
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Re: Changing prop shaft gland packing
Doug, Call Sam's Marine. Steve McPhereson will know what size packing to use and they'll have it to sell. We've all said we'd support something for this forum, so my version is to just buy from Sam's whenever it makes sense. :)
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Re: Changing prop shaft gland packing
Quote:
Originally Posted by mike
Doug, Call Sam's Marine. Steve McPhereson will know what size packing to use and they'll have it to sell. We've all said we'd support something for this forum, so my version is to just buy from Sam's whenever it makes sense. :)
Good one Mike, I recognize it. I thought Sams wouldn't have GFO, but worth a call.
Doug
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Re: Changing prop shaft gland packing
Doug one other word of CAUTION...
we have a friend with a 53my '78. Had a wobbling, leaking packing gland, stb side. He changed out the packing and tightend everything up properly. BUT, on their first cruise after (vs checking in gear at the dock) heres what happened:
the previous wobbling effect had LOOSENED THE ENTIRE PACKING TUBE on the pedro (fiberglass tube thats integrated into the hull that the whole works clamps to). It CAME OFF now leaving about a 4inch hole in the hull 3ft below the water line! and because it had spun the packing nut(s) around they smashed the glass in the raw water strainer!! (871's) another 4" water hole! in the raw water intake.
Now, in the blink of an eye, youve got about 500 gallons a minute coming into the engine room. His high water, stb side lit up first then before he could even get down below, the gen room high water lit off. At this point the only thing higher pitched than the alarms was his voice on the radio!!!
This became a serious serious problem in only minutes. He thought the (only) problem was the smashed glass on the strainer, so shut it (by reaching under water, then ran and shut the engine down. STILL not knowing or being able to see that the entire gland had spun off the tube as all his fuel manifolds are just about there. So while he thinks hes stabilized and the pumps will catch up, water is still pouring in...
Long story short, they saw the water still rising, found the tube problem and with pillows blankets etc slowed the leak til the CG came alongside with pumps. Then towed to the yard and into slings.
Anyhow Doug, point of the story is if its wobbling check EVERYTHING on the tube, including the hose clamps!! look for newly exposed surfaces to see if infact it (the hose) has moved at all.
good luck.
geoff58yf
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Re: Changing prop shaft gland packing
I would think that you would have to have the packing spinning in a bunch. With a loose glan nut,to cause the whole shaft log to run off center. Bill
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Re: Changing prop shaft gland packing
OK, I'm going to be the wet blanket here.....I would not do a procedure on the boat which I hadn't done before, involving opening the bilge to seawater, without being at least once familiar with it. AT least make sure everything else is totally okay before starting this. The thing that bothers me is that this isn't a routine change of packing material- he's doing it because it's not acting right and running hot. This isn't the one to learn on, if you ask me, especially with the boat in the water.
If you're determined to do it in the water, do it at the marina and make sure they know about it so if you need an emergency haulout, you have a prayer of it. OR, do it in the lift well over lunch when they haven't got a boat in the slings, so if they need to haul you out pronto, they can do it. I realize I sound like an old lady. Sorry.
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Re: Changing prop shaft gland packing
Naw, if something goes dramatically wrong stuff a towel in there and head for a lift on the good shaft/engine. You can easily stuff enough in there to slow the water to a trickle, and if you have working pumps this is not a big deal.
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Re: Changing prop shaft gland packing
OK, Karl, you are braver than I am.... :D
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Re: Changing prop shaft gland packing
Is that :cool: or is it :eek: ?
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packing method for less water intrusion
Jim,
With some saran wrap, a towel and some duct tape, you can totally stop ANY water from coming in past the shaft while you repack. I repacked our 53's stuffing boxes this weekend. I don't think I got more than one gallon of water in the boat - total from both shafts.
I wrapped the towel with saran wrap, moved the packing gland up the shaft, wrapped the saran wrap/towel around the shaft/packing box with the saran wrap against the shaft/box and taped it. The only water that comes in occurs as you are removing/replacing the gland itself.
Actually, not that much water comes in anyway, certainly not enough to be concerned about if, as G says, the bilge pumps are working. On my previous boat I never worried about it and the amount water that came in never even raised the float switch enough to activate the pump. I wasn't sure about this with the 53 since it was my first experience with this boat but I don't think I'd bother with wrapping next time.
I used regular packing instead of GFO because there is a 50 ft spool of it on the boat. If I didn't have it, I'd go with the GFO..
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Re: Changing prop shaft gland packing
My tube has a "droop" to it so the gland is not perfectly centered around the shaft. It's close to the shaft on the top and farther away on the bottom. I figured I'll loosen the aft end hose clamps and reposition the tube so it's straight when I have the packing material out to pack the gland. Maybe that's a reason to do this hauled?
Doug
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Re: Changing prop shaft gland packing
i was also aprehensive the first time around but it turned out to be pretty easy. plus on the 53MY they are easy to reach.
i used standard packing the first time around without any special tool and it took a while to get the old stuff out. It still leaked so i redid it with GFO and the proper extractor tool (flexible corckscrew...) : Much easy.
the nice thing about the GFO is that it doens't require any grease which make the hwole experience very unpleasant as that special lubircant sticks to your hands...
the port still drips a little but i don't want to overtightened it as i found that one of the 2 bolt had some stripped threads forcing me to add a second nut. not ideal but it will do for now. Shaft may have been scored in the past, we'll see whenver i have to haul out the boat.
I 'm pretty sure i used 1/2 on my 1970 53my but one package isn't enough for 1 gland. I think it took 4 rings so 3 packages neeeded for both engines. check the size of one ring, x 4, you get 30" per package
my port side gland isnt' aligned very well either but I'm reluctant to mess up with the clamps in water...
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Re: Changing prop shaft gland packing
I used three rings on my mains. I could get a forth one in there, but didn't see the need, as the three didn't leak.
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Re: Changing prop shaft gland packing
Just pulled our 53MY on Moday, pulled the packing today and found the same poor alignment problem. It was tight on top, lose on the bottom of the gland. When looking at the bottom I noticed that the log angle cut out is set up to accomidate a shallower angled shaft. I believe Hatt designed the log to work with both the 58' and 53' hull. The log angle appears to be set up for the 58', it may be a compromise. I will also try to reposition the log hose but I am not hopeful. By the way the log takes 1/2" packing, i am using GFO.
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Re: Changing prop shaft gland packing
You can have to much packing in the cap. If I remember correct they were only designed for 2 wraps. If you notice when you have the cap off the male end of the shaft log has a ( V ) taper,tapering in. So when you tighten the cap,which is flat inside, it forces the packing into the (V)around the shaft sealing the shaft. If you have to much packing. You must use a lot more force to tighten the cap to get it to seal. Also it could just bunch up in the cap and may not seal proper. Which could cause the shaft log to run off center. This is the case where more is not better.You should almost be able to tighten the nut by hand. Just make sure you have the correct size packing. Make sure you cut the packing on a 45 Deg. and put the cuts 180 Degs.from each other. Just because you can get more packing in the cap does not make it correct. The added threades and space in the cap are required to withstand the compression force on the seal and keep the threads from stripping. Bill
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Re: Changing prop shaft gland packing
Quote:
Originally Posted by Trojan
You can have to much packing in the cap. If I remember correct they were only designed for 2 wraps. If you notice when you have the cap off the male end of the shaft log has a ( V ) taper,tapering in. So when you tighten the cap,which is flat inside, it forces the packing into the (V)around the shaft sealing the shaft. If you have to much packing. You must use a lot more force to tighten the cap to get it to seal. Also it could just bunch up in the cap and may not seal proper. Which could cause the shaft log to run off center. This is the case where more is not better.You should almost be able to tighten the nut by hand. Just make sure you have the correct size packing. Make sure you cut the packing on a 45 Deg. and put the cuts 180 Degs.from each other. Just because you can get more packing in the cap does not make it correct. The added threades and space in the cap are required to withstand the compression force on the seal and keep the threads from stripping. Bill
Trojan,
53MYs do not have a threaded cap. The cap is a collar with two threaded studs which have nuts to do the squeezing. GFO recommends 90 degree difference in cut placement. Your logic still applies though: more is not necessarily better. I'll use 3 rings like Genesis did.
Also, I think you're right that the whole packing is spinning, which is the cause of the wobbling gland when running.
Thanks,
Doug
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Re: Changing prop shaft gland packing
a few comments/questions-
Back in the early 80's, one could buy the traditional flax/beeswax type packing or teflon impregnated. I thought the teflon sounded slick (yeah, pun intended) and specified it on a 4" shaft for a seiner. My thought was it should reduce temperature at a given squeeze force. Is the teflon still around? I had not heard of GFO- it must be slick as well...
On spinning the packing- This sounds odd to me. The shaft is smaller dia and probably smoother than the gland. Why on earth would the packing spin in the gland vs the shaft?
On wobble- If I had this, I think I would do shaft alignment at next haulout and strive to center the shaft in the log. I mean, alignment does not last forever, things settle and shift. My old sailboat auxilliary was out of line at some point in the boat's life and the shaft log was ovaled on the inside. The wall thickness was getting thin! Fix would have been a bitch as the log was a complicated casting that had the rudder hole integral.
Gary
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Re: Changing prop shaft gland packing
In a previous post he said the log wobbled and the shaft was in line.That would seam to be the only logical answer. More like bunching of the packing caused by a loose nut or old packing left in it. I agree it would be odd. But there are stranger things. Bill
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Re: Changing prop shaft gland packing
Found 4 packing rings in the shaft log. Also found the raw water intake seacock valves to be trashed. It's a real bear to remove the 2 1/2" seal nut, 5200 is tough stuff, it required a 4' pipe extension on a breaker bar to get enough leverage. I can report that the hull in the intake area is a full 1" thick.......and luckly found no delamination. mike
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Re: Changing prop shaft gland packing
Mike,
Were you able to correct the alignment of the packing gland versus shaft and log? I don't know whether to try it on the rear (shaft log) side of the hose or the gland end of the hose. It seems like the shaft log side would adjust it better, but is that end pre-determined by the shaft log geometry instead of how the hose is attached? And do they put the shaft log hose on with some kind of sealer, making it almost impssible to move by just loosening the hose clamps?
Thanks,
Doug
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Re: Changing prop shaft gland packing
Doug,
I have not got that far along, still working on fixing the raw water intake. But at first glance it appears that both hose ends will have to be adjusted on my setup. When I removed all the packing the log sat down on the shaft. There is a tremendous amount of down pressure from the log hose. It is very apperent that the hose connection and alignment is critical. I don't believe a sealer is used between the hose, log and gland. But if one is concerened you could use Merc-cruser bellows glue, I have used it with great success on my old TRS drives in my offshore sport boat. The only problem is you have to be high and dry to use it. By the way, 3" long sheet rock scews driven into the packing makes for a good removal tool. Drive one in and pry it out with vise grips,...works great, just make sure you bias the screw away from the shaft and toward the log body. Mike
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Re: Changing prop shaft gland packing
So thanks to this group, I repacked both of my prop shaft glands today (wet) with GFO. It took 3 hours because "nothing is ever simple". They're practically drip-free after 2 hours of running and a little adjusting. I'll watch them closely for another few running hours in May. Here's some "Lessons Learned":
1. The water coming in is not bad. Maybe a gallon in 2 minutes. The bilge pumps keep up with it easily (Rule 2000 pumps).
2. Mike absolutely saved my arse from a much longer ordeal digging out the old packing by recommending 3" long drywall screws as extractors. It's REALLY HARD to get the old flax stuff out and I had made a few sharp bent pick things to try, but with the drywall screws you just screw them into the flax and grab them with a vise grip and pull. THANKS MIKE !!!! I tried my pick things and a dental pick but that stuff is WAY stronger and wedged in way tighter than picks can get out. Only problem was I wanted 4" drywall screws to get at that last layer at the far end of the gland.
3. GFO works great. I knew to cut it at a 45 degree angle, but I didn't know which way the angle was supposed to be (overlapping front to rear or overlapping outside to inside. So I alternated them in the layers.
4. The fit of the 2 collars keeps any misaligned gland angle from misforming the GFO too much. Mine is too close on the top and too far on the bottom, but the collar minimizes that.
5. You use the collar to push in each successive layer of new GFO. The studs are long so the nuts tighten the layers in just fine.
6. I found 4 layers of flax and the wobbling port gland had a 5th partial layer that was a wad. I think it was incompletely removed from the previous time it was packed and was spinning like a wad at the bottom layer. I put 3 layers of GFO back in.
7. Both glands still have an almost imperceptible wobble when running, like maybe a 32nd or 64th inch. I'm going to let it go and watch it. The hoses were clamped stongly and had not moved on the shaft log any (thanks Jim). I'll watch that too. If Mike is successful in realigning glands by adjusting his shaft log hoses, I'll try that too whenever I have it hauled but it's $500 to haul at my marina that I don't want to spend.
Thanks again,
Doug Shuman
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Re: Changing prop shaft gland packing
They never run true true. That is why they use packing and a rubber boot instead of a seal or O ring with a solid mount. Glad you got it done. Another one under your belt. With stories like this. We will all start doing our own work. Sears have a regular packing remover kit. Bill
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Re: Changing prop shaft gland packing
West has a corkscrew pick on a flexible shaft with a T-handle on the end that works well.
Screw in and PULL.
Just don't get a defective one. I had one that wasn't swaged together properly and the pick part came out of the barrel when I yanked on it. That really pissed me off, because I then had to go get another one, and had a piece of pick in there which meant I had to get that other one RIGHT NOW and take care of it.
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Re: Changing prop shaft gland packing
It's a bit late for this...but there is a solution that un-bonds polyurethane adhesives such as 5200. It is called Anti-Bond and boating stores have it, at least West does. It helps somewhat.
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Re: Changing prop shaft gland packing
Doug,
Why only 3 rings of GFO and not 4 ? I am getting ready to do the packing on this Wed. What made you decide to go with only 3?
I have been out a week now working on my Naiad stabilizers...what a pain in the arse. Had to remove and replace bearings and seals...so much for their "life-time seals" claim. The seals were fine, they just allowed water in to get at the bearings. Also had to replace both seacocks for my mains. By the way I found that some yard-bird put my water pick-up stariners on with inch long screws and penetrated the inside of the hull, causing local delamination. Had to dig it out, dry it and epoxy back fill. Mike
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Re: Changing prop shaft gland packing
Mike,
Genesis put 3 rings on his, the GFO package said three, and there was just enough GFO in one package to do three.
I didn't try to adjust my log hose (too scary in the water!) so I'm interested in yours. There was a lot of downward pressure on the gland, pushing it closer at the top as we discussed. I found that by placing the GFO on a very smooth flat surface and pounding it a little flatter with a hammer, that I could get it squeezed in easier at the top where it's tight. You carefully remember which side was on the flat surface (I used the GFO label side as a marker) and put that side of the GFO against the shaft so there are no "dents" from the hammer on the shaft sealing surface.
If I were out of the water, I'd loosen just the aft hose clamps and try to spin my whole gland and hose 180 degrees so any hose droop is now upward pressure. If the hose is straight, then the problem is in the shaft log design, as you indicated. ("Shaft Log" is that fiberglass, log shaped, hose holder that the shaft goes through as a through-hull in the boat. On a bare hull, it looks like a log.)
Tell me how it goes.
Doug Shuman
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Re: Changing prop shaft gland packing
Doug, thanks for the info. I can get a finger in the bottom gap on the log, the top sits right on the shaft. I'll try to give it a go with your idea of reversing the packing gland 180 deg., assuming I can get the log hose loose with out tearing it up. I want to avoid removing the coupling from the shaft...that is a real pain. I'll keep you all posted on my success or failure... thanks, mike
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Re: Changing prop shaft gland packing
Mike,
If you can't spin it 180 - I used a 2" dia. 3 ft. long pipe placed on the hull and against the bottom of the gland as a lever to lift it up to get the GFO in. I would think that a car scissor jack with one or two bricks as a base might hold it in any position more easily, or even lift it after you undo the clamps. You'd have to be careful not to apply too much force with the scissor jack.
Doug
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Re: Changing prop shaft gland packing
Am reading w/ interest this thread as after my last run I have developed a 2 drip per second leak on the port shaft log. BTW I noted that the shaft did not use to turn while in neutral, then began to slowly turn and after the last run began to leak. The logs were previously almost completely dry. I have enclosed a picture of the culprit (the actual shaft log does not have any letters on it, ha ha) but I would just like to confirm that it is letters A - D that I am cranking down on to stem the flow.
Also, what kind of operating temps should I expect and where exactly should I read off? Shaft, log etc...
Thank you for the FIX YOUR HATT BY THE NUMBERS lesson.
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1 Attachment(s)
Re: Changing prop shaft gland packing
Here is the picture. Thanks
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Re: Changing prop shaft gland packing
Nope - it is "E" and "F" you turn to cinch down the packing.
The others are the log hose clamps - if they're tight leave 'em alone. Cranking them won't stop the leaking if its the packing.
(PS: Nice spray deflector on the shaft! I like it!)
PPS: Next time you CHANGE the packing run a nut down each of those long studs BEFORE you put the collar on. That way you can use them to jack off the collar the next time you need to get in there to change it. Its a royal bitch to get it out otherwise....
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Re: Changing prop shaft gland packing
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Re: Changing prop shaft gland packing
Now now, let's keep it clean around here.... :rolleyes: