New Shaft Seal?

Hello

The shaft going down to my props is starting to leak, it's always been dry before. It drips almost once per second so I'm assuming I need to replace a seal? If so is this something that can be done while the boat is in the water or would it need to be hauled out? Thanks in advance for any help. I've attached a pic for reference.

It needs to be tightened or repacked. If the packing is still good then you can tighten the bolts a bit and it will compress the packing which will make the packing squeeze the shaft more and stop the dripping. However if the packing is too old and is getting hardened then you can score the shaft which isn’t good. You can repack it if the packing is too old. How long have you had the boat and do you know when it was last repacked? You can repack it in the water but you will get a good size gusher of water when you remove the old packing. You will probably need a packing pick, kinda like a corkscrew to pull the old packing out. You need to know what size packing you need. I would recommend getting someone who know what they are doing to do it in the water the first time you are going to do it.

Thanks for the reply. We've had the boat since January and I'm not sure when the packing was last replaced.

It being dry until recently is a bad thing. Those seals need to drip to stay cool. If it did not drip and now has started I believe it is an indication that it became overheated and needs to be repacked.

Although it can be repacked in the water, it is not a job for an amateur
or the feint of heart. Best to pull the boat and then do it yourself or have the yard do it. If you have a few dollars laying around you can have the yard install a new dripless seal. These dripless seals force water from the exhaust line into the seal. They actually still drip, but the drip is from the front and out the back of the boat. Mine cost around a thousand a few years ago but the plumbing was already in place. I'm guessing you are looking a couple thousand.

pete

The packing hardens over time and won't tighten down, depending on the material the packing is made of. IF you can seal off the shaft at the cutless bearing on the outside of the hull you can repack it yourself, it's not hard. If you can't there is a fair amount of water flow while still in the water that would make repacking harder to accomplish.

Look for an article on repacking online so you know what you are looking at having to do.

Thanks Pete

how much should they drip when working properly? Do they only drip when the boat is being run? I'll definitely have someone else fix em

I have done it in the water many times. And I am not terribly handy. I have not seen a packing gland like that though...I am used to the screw and counter screw setups. Anyway, while working properly they should drip once every 2-5 seconds maybe?? That is just a WAG. And maybe no drip while not underway. A drip here and there at rest is no cause for concern.

Flboy,
If it were me, and I didn't know a whole lot about how to repack a shaft seal, I would not attempt it with the boat in the water!
Remember, that packing is what keeps the water out, and if something were to go wrong after the removal (or partial removal) of the old packing, it could mean TROUBLE. Now remember, I am often considered conservative in my thinking
As far as repacking the old seal or moving to a new dripless seal, there are pros and cons to both.
Good luck

I wanted to repack my stuffing boxes the first time with the boat in the water - I'm a risk taker - but I didn't want to do it alone. Several threads here on the topic ranged from "it's no big deal" to "I'd never do it, too scary." I prepared my wife to be my repacking partner: "I'm going to unscrew the packing nut (or gland), slide it down the shaft, and the water is going to come gushing into the boat! It'll be scary!" I told her I'd knock the water down by wrapping it tightly in strips torn from a cotton T-shirt (read that somewhere) and that the bilge pump should easily handle the water coming in the boat. I assured her that if we were uncomfortable at any time, we could back up and start over or save it for another day.

Of course I checked to make sure that the bilge pump's float switch was turning on the bilge pump and that the bilge pump was actually pumping water. I had tools ready to dig out the old packing, new packing cut to length, and T-shirt strips nearby. My packing is only 1/4-inch, and I was concerned there wouldn't be much room to work at digging it out, so we had options.

Here's a picture of the water flow after removing the nut and wrapping the shaft several times with a 4-inch strip of T-shirt and tying it tight (I was going to wrap the T-shirt strip with the rope you see there but decided that it wasn't necessary):



I can't comment on the amount of water coming in the boat before wrapping with the T-shirt, because I was busy. It wasn't scary, and the water wasn't a significant distraction. Those are my wife's hands to the left, busy digging out the old packing while I watched, cheered her on, and took pictures. The bilge pump was running every 4 or 5 minutes.

After it was over, my wife said that I'd gone too far describing the experience as "the boat's sinking while we're working," and that it was no big deal.

Hope this helps, but I'm sure every situation is different.

Greg.

GregBrannon said:

Several threads here on the topic ranged from "it's no big deal" to "I'd never do it, too scary."

Greg.

Click to expand...

The "It's no big deal" people are likely the people that have actually done it. ANd I agree...it is no big deal.

The "I'd never do it " people are obviously the people that.....wait for it.....HAVE NEVER DONE IT!!!!!

There are two schools of thought on packing placement. One is a one piece wrap of about 5 turns around the shaft. The preferred method is to cut 3 to 5 loops with tapered ends and place them alternatingly so the joints do NOT line up.Cut the packing ends at an angle giving water less of a path.

In your instance you can have these rings of packing precut to the proper size beforehand . Once you pull the gland apart and dig out the old packing it will get wet but the gush will slow as soon as you insert the first ring and stop almost entirely by the third or fourth loop.

Tighten it down until you get just on occasional drip. Run the engine and tranny and it should drip every few seconds. You might get or borrow an infrared heat sensor and shoot the gland when you are underway. I'm not sure what it should be but guessing under 100 degrees.

pete

Back the two nuts of, left and right. Then back the outer side of the gland off.

Stop.

Too much water? If so, just put the gland back together.

Next, pull the first ring out.

Too much water? Stuff it back in and put the gland back together.

If not, grab the ring, stuff a paper towel in there and put the gland back together and go shopping for packing.

You get the idea. If you go slow, most people are amazed at how little water actually comes in.

First time, buy a little extra packing. Buy an extra corkscrew removal tool.

Bet your heart rate never gets up.

The whole point, is that you can control the situation each step of the way. It’s a stuffing box, at any time you can stuff whatever you like back in there, reassemble the gland and stop the water. Might not want to run it that way, but if you need to go home, come back tomorrow, lots of options.

It really doesn’t need to be overly stressful.

Much safer to replace packing than risk tightening old hard packing. That’s what you should fear most.

Pete Meisinger said:

There are two schools of thought on packing placement. One is a one piece wrap of about 5 turns around the shaft. The preferred method is to cut 3 to 5 loops with tapered ends and place them alternatingly so the joints do NOT line up.Cut the packing ends at an angle giving water less of a path.

In your instance you can have these rings of packing precut to the proper size beforehand . Once you pull the gland apart and dig out the old packing it will get wet but the gush will slow as soon as you insert the first ring and stop almost entirely by the third or fourth loop.

Tighten it down until you get just on occasional drip. Run the engine and tranny and it should drip every few seconds. You might get or borrow an infrared heat sensor and shoot the gland when you are underway. I'm not sure what it should be but guessing under 100 degrees.

pete

Click to expand...

I’ve never seen packing applied in a continuous strip, wound around the shaft.
IMO, that would not work well, if at all.
If you use a “modern” packing, such as GFO and plenty of silicone grease, you can expect no drip.
Care must be taken not to over tighten the packing, it needs to be tightened in small increments, to get it seated just right.
Search this forum for lots of discussion on the subject, Google it for more.

If you put it in a continuous strip, I think that the water would just flow around and around until it came out inside.

I`ve never done it. Even with ghost`s helpful "how to" crib notes, before losing my stuffing box virginity, I`d like someone with me who had "done it".
And, what`s that seal in the pic, and where did it come from?

"how much should they drip when working properly? Do they only drip when the boat is being run? I'll definitely have someone else fix em"

NO drips ,not a drop , ever if repacked with a modern packing like Duramax.

The old flax , teflon and other styles has been replaced with far superior materials.

Your stuffing box would be really easy as its so easy to get to.

You can do it first time , but the challenge is having the correct size packing ready to use.

A full service yard should have the various sizes in there chandery .
If they do a short haul, staying in the straps , no blocking would be quickest and cheapest.

A half hour of work at the most.

Be sure they have Duramax its competition on hand so they dont stick you with 1950's vintage old stuff.

I had a Willard 30 Searcher which is a unique style. Stuffing box was accessed via a small cabinet in the head that required a contortionist. This was long before the internet and I had the same question - did I need to haul to replace? Answers were far fewer, but were essentially the same as this thread - but came from books instead: ranges from its possible to don't do it. I was pretty broke and, with a pit in my stomach, decided to give it a try.

I was amazed at how little water came out even on this displacement trawler where the prop shaft was relatively deep in the hull/water. Bilge pump easily kept up. As a side note, the shaft was mildly scored, likely due to the lousy access to the stuffing box. I dressed the shaft - with the nut backed-off and the engine running and trans in gear, I held strips of wet/dry sand paper against the shaft. Worked like a charm!

I have since repacked many shafts (and field dressed a few more). My general rule is the stuffing box should not drop at rest, and at most drip ever several seconds when running. Also, when running, it should not heat up (if seen where they get so hot that water will steam). If this balance cannot be held, time to repack.

By far the most difficult part of repacking for me has always been figuring out what size packing to purchase.

I have also repacked a box while in the water. Actually that's the only time I have ever done it, in the water.
Water did NOT gush in, it flowed gently. The aft, small bilge pump easily kept ahead of it.
I was always told 1 to 3 drips per minute was a good rate while under way. Less while at rest is ok.
As far as temperature, 10 degrees F above ambient is what I read is a rule of thumb.
Good luck with the project.

Bruce:

A little arithmetic:
area of discharge hose= (inside diameter of outlet of Rule 1500 pump is 1"), so 0.78 sqin.
area of stuffing box empty = (1/2" stuffing around a 1.75" shaft) 5.94-2.40=3.53 sqin. so 5.8 times the instantaneous capacity of a Rule 1500.
Take 1 minute of full flow through your stuffing box with the stuffing removed and your bilge pump will clean it up in 6 minutes.
If, like most of us, you have more than a single 1500 gph pump, way less time.
Allow a realistic time of full flow, like 3 to 5 seconds, and your bilge pump will barely notice it.

I'm another who has done the repacking a number of times starting long before the internet was even around. I found the water inflow was not great and the BP easily kept up. Other than the available books I was on my own as there is room in there for one person at a time.

I made a couple picks to dig out the old packing and then found corkscrew type tools for this purpose are available at the chandleries. May have to be ordered.

https://www.jamestowndistributors.com/userportal/show_product.do?pid=3861

Actually any good seal shop, Orings and packings, will have these things also.

I used razor blades to cut the packing into rings by wrapping a piece around the shaft using the part of shaft that was NOT in the stuffing box. They are sharp so be carefull. A very sharp utility knife such as the Olfa with a new blade will do well also. You don't need to press hard to get the stuff to cut. Even better would be approaching a prop/shaft shop and seeing if a short piece of shafting of your size can be had and then used as an arbor to cut them at home.

Cut the ends on an angle such as 45o. The angle does not need to be exact, just so the angle closes [mostly] as the ring is wrapped around the shaft.

Tamping with screwdrivers will likely punch a hole through the packing. It will close later as the box is tightened but better to not damage it.

Install the ring and use a tamping tool made of PVC pipe cut in 1/4's .
I made the tampers ahead of time. They only need to be 1/4 the shaft circumference and push gently working the ring into place. Then place the second and third rings repeating the tamping.

I used to install 4 or 5 rings but found it was not needed and actually made adjusting more difficult.

Install 3 rings [or a 4th] with the ends arranged approx 120o from each other so the ends do not line up , ring to ring.

Then install the stuffing box compression ring and tighten the nuts up EVENLY a bit at a time. DO not just screw one side down and then the other. The packing needs to be compressed evenly.

I would grease the stud and nut threads with water resistant grease. Outboard shaft grease is great at this but others are available.

Adjust so the water stops. Then run the engine in gear, it will likely start to leak again, and snug up some more untill the water is a slow drip of one drip every second or two. Do not just fast crank the nuts. Once adjusted set the jam nuts.

Then run the boat , a real run, for a couple or so hours and check and adjust again as needed.

I have gone through the typical wax impregnated flax packing, the TFE impregnated flax packing, the clay stuff [forgotten the name] and now use the GORE GFO packing. The older ones I repacked every two years.

THe Gore was last done more than ten or twelve years ago and all I need do once I got the adjustment is snug it once or twice a year to keep the water under GOOD control. It takes very little now. I do not try to totally stop a drip.

With all packings compress slowly allowing the packing to completely close any voids and conform to the shaft. It needs to flow slowly to do that.

I also cover the stuffing box. I use an old fender hacked to do that but other materials will work also. ALL stuffing boxes weep some water. Thats how even the so called dry seal ones lubricate themselves. There is more to it but they do allow a FINE spray. THe spray is so fine you can't see it except by holding a blue Scot paper towel next to it . A good one will take several minutes, maybe more, but it will dampen that towel. That spray will travel causing rusting of any engine or gearbox , or other steel parts, nearby.
The cover will stop that spray from spreading by collecting it and then the accumulated water will drop into the bilge. Just leave the bottom of the cover slightly open. The cover can be clamped lightly into place with a Tridon clamp or Tyraps. It is easily removed or moved at adjustment time.

I just did it for the first time. Was quite anxious beforehand. I would cut your new packing first and have everything ready and in arms reach but honestly no big deal. Did it in water.

Wow, just got back to checking this and thank you for all the replies and how to information. Gonna run down to the boat and take a look at it but I'll probably find someone who can help me with my first attempt at this. Thanks again everyone, I really appreciate the help and information.

Really, ITS NO BIG DEAL. Anyone that uses the word GUSH to describe the flow has never done it before. The flow is so slight that you could leave it to go get the right sized packing for an hour and the bilge pump could easily keep up. If not, then you need to replace the bilge pump. After you do it the first time you will look back and laugh at your fears. I believe that I could run the boat with NO packing in it and I would be in no danger of sinking as long as I had a bilge pump.

Best way is to replace

I think that the best is to replace it by a PSS Shaft Seal.
Please give a look to this link
https://www.shaftseal.com

I have this in our Trawler since 1999 and no one problem no one drop.
Very little maintenance or nothing

Anyway...in our other boats I also had to repair it on and out of the water

Good luck

armando said:

I think that the best is to replace it by a PSS Shaft Seal.
Please give a look to this link
https://www.shaftseal.com

I have this in our Trawler since 1999 and no one problem no one drop.
Very little maintenance or nothing

Anyway...in our other boats I also had to repair it on and out of the water

Good luck

Click to expand...

You do know that you are supposed to replace the bellows every 6 years, don’t you? There is maintenance to them.

Comodave said:

It needs to be tightened or repacked. If the packing is still good then you can tighten the bolts a bit and it will compress the packing which will make the packing squeeze the shaft more and stop the dripping. However if the packing is too old and is getting hardened then you can score the shaft which isn’t good. You can repack it if the packing is too old. How long have you had the boat and do you know when it was last repacked? You can repack it in the water but you will get a good size gusher of water when you remove the old packing. You will probably need a packing pick, kinda like a corkscrew to pull the old packing out. You need to know what size packing you need. I would recommend getting someone who know what they are doing to do it in the water the first time you are going to do it.

Click to expand...

That's exactly what we did - hired someone to replace the packing while in the water - so glad we did! They had to heat up the housing and it took a while to get the old hard packing out - thankfully they had quoted me a fixed price for the work. Replaced with modern 'Gortex' type packing that can be tightened so no leaks necessary - and ours has a cooling water line anyway.

flboy said:

Wow, just got back to checking this and thank you for all the replies and how to information. Gonna run down to the boat and take a look at it but I'll probably find someone who can help me with my first attempt at this. Thanks again everyone, I really appreciate the help and information.

Click to expand...

Make sure you get all of the old packing out before putting in the new rings. The last ring can be packed in tightly, may break apart when you are trying to pull it out leaving a section behind without you realizing it. Could happen. Trust me on this.

Prepare your self with all tools required, gland packing, rags, functioning bildge pump etc and just do it, it is the only way to learn about your boat and your own capabilities I have done it many times without drama

Several packing tool kits are available from Grainger too. Packing is commonly used in industrial pumps as well. Although I have never changed packing on a boat I have broken or partially straightened out several pigtail or pick tools, so you many want to have more than one ready to use to get that last 20 year old ring out. No matter what packing type we use we always let them drip to to make sure we don't over tighten.

When I have tough packing...I just use long, fine threat drywall or decking screws....then pull them out with vice grips. Drive 2-3 around the shaft.



I have broken too many of the corkscrew packing tools to count.


I find with the modern packings, you can tighten so you get more of a wet ooze than a drip....stays cool and keeps the bilge dryer.