Leaking stern gland

[notts_alan]

Anyone have any experience with this type stern gland .

I have tried nipping up the 3 Allen bolts but still leaking.

[Tracy D'arth]

I don't know that one but the single allen screw on top I suspect is for grease, usually silicone, to be occasionally injected and the water supply on the top is for lubrication and cooling. It will have one or possibly several lip seals inside. The shaft shows signs of fore and aft movement, is there no solid plummer block bearing on the shaft?

[Tony Brooks]

That is because it is not a packed gland. As a very, very long shot take the vertical alan screw out and squirt some special Vetus/Volvo stern gland grease into the void below, you just might get lucky. Otherwise, it is but a new seal assembly, take the shaft coupling ff and change the seal.

[notts_alan]

1 hour ago, Tracy D'arth said:

I don't know that one but the single allen screw on top I suspect is for grease, usually silicone, to be occasionally injected and the water supply on the top is for lubrication and cooling. It will have one or possibly several lip seals inside. The shaft shows signs of fore and aft movement, is there no solid plummer block bearing on the shaft?

It was fine until I hit a submerged object , it stopped the engine dead . This is the first time down engine bay since that happened a couple of weeks ago , I suspect that object has moved the shaft

I will get some grease and try the top screw

[ditchcrawler]

7 minutes ago, notts_alan said:

It was fine until I hit a submerged object , it stopped the engine dead .  

Have you checked the state of your prop and if the shaft has moved where it clamps into the coupling. If it stalled the engine also check engine mounts for damage 

[Tony Brooks]

I might be the prop is now bent causing the shaft to shake about because that type of gland is usually coupled with a rubber Cutless bearing at the back of the stern tube. If so, that would make the lip seals leak.

[notts_alan]

I have ordered some vetus grease . I only noticed bilge pump turning on when leaving boat and had a quick look and noticed the drip , I started engine and mounts seemed OK,  tried a quick nip up on bolts but then had to leave . 

Grease should arrive Monday so will grease and investigate further then , get a bit more hands on .

Thankyou everyone for replies .

[booke23]

I had one of these Vetus dripless stern glands on a previous boat. They are very sensitive to shaft alignment (otherwise they drip) so the above suggestions to check engine mounts and shaft condition are where I would start. Have you looked down the weed hatch to try and ascertain the condition of the prop? It's worth taking the allen screw off and applying silicone grease, but in my experience it won't make much difference to any drips. In any case Vetus recommend applying silicone grease every year or 150hrs. 

[Tony Brooks]

30 minutes ago, booke23 said:

I had one of these Vetus dripless stern glands on a previous boat. They are very sensitive to shaft alignment (otherwise they drip) so the above suggestions to check engine mounts and shaft condition are where I would start. Have you looked down the weed hatch to try and ascertain the condition of the prop? It's worth taking the allen screw off and applying silicone grease, but in my experience it won't make much difference to any drips. In any case Vetus recommend applying silicone grease every year or 150hrs. 

 

Yes, and pulling the seal assembly forward and descaling the shaft far more often than Canal Boat builders would seem to admit.

Edited March 8 by Tony Brooks

[David Mack]

7 hours ago, notts_alan said:

I have tried nipping up the 3 Allen bolts but still leaking.

I would expect those Allen bolts to be tight anyway. If they were loose enough that you could nip them up then water could be getting through the joint behind the front part of the gland and/or you could have lost some of the grease by the same route.

 

Can you actually see it leaking? How many drips of water per second (or seconds per drip). A continuous dribble is worrying, a drop every few seconds can safely be left for a week or more between manual bilge pumping.

[blackrose]

For future reference you didn't need to order expensive silicone grease from Vetus as any thick silicone plumbers grease will do. It's available on Amazon, eBay or from your local plumber's merchant. But at least you've got something to compare the consistency of any new grease you order, as there is also a thinner, less viscus variety which you shouldn't use.

 

Every couple of years instead of trying to squeeze a tiny bit of grease through the hole at the top of the gland, I remove the 3 bolts from the front of the bronze housing and slide it up the shaft so that I can pack a bit more grease in there. Water will come in at the rate of about a litre a minute but that has the benefit of flushing any detritus out of the gland. I think there may be a gasket in there (can't remember) so just be careful in case one side of the gasket stays with the housing and the other comes away with the front part. You don't want to break the gasket. Slap some silicone grease in and refit the front of the housing tightening the 3 screws evenly.

 

A rough way to check the shaft alignment is to turn the shaft by hand. If it moves reasonably freely that's good. Next start the engine and put it into gear and look down from above. Close one eye and see how much the shaft wobbles from side to side. If it doesn't then chances are it's roughly aligned.

 

The next thing I'd try is loosening the gearbox shaft coupling and moving the shaft backwards or forwards by just 5mm in the coupling before re-tightening. The reason for this is that over time the seal will wear the shaft so what you're doing is just exposing the seal to a fresh, unworn area of shaft and that may seal it.

Edited March 9 by blackrose

[ditchcrawler]

1 hour ago, blackrose said:

 

The next thing I'd try is loosening the gearbox shaft coupling and moving the shaft backwards or forwards by just 5mm in the coupling before re-tightening. The reason for this is that over time the seal will wear the shaft so what you're doing is just exposing the seal to a fresh, unworn area of shaft and that may seal it.

I think his shaft has already come forward 5mm looking at the photo, 

[notts_alan]

Thank for the input , grease arrived.

Checked prop and no damage , load of rope and fishing net around prop , cleared it all off , no movement on shaft so prop seems fine.

Engine mounts seemed OK,  no unusual vibrations or sounds.

Shaft alignment looks OK.

Shaft couplings and flexible joints all look OK.

Took grease screw out and forced grease in past the jet of water spinning shaft by hand , that slowed the drip right down , ran engine in gear for 5 mins and repacked .

Thankfully now no dripping at all .

I thought about removing the front off buy was not brave enough , I thought water would piss in.

[booke23]

3 minutes ago, notts_alan said:

Took grease screw out and forced grease in past the jet of water spinning shaft by hand , that slowed the drip right down

 

There was a jet of water coming out of the grease hole? That's distinctly not normal. 

[Tony Brooks]

1 minute ago, booke23 said:

 

There was a jet of water coming out of the grease hole? That's distinctly not normal. 

 

I think the seals are in front of the grease hole and the shaft bearing is usually a fluted Cutless rubber bearing with longitudinal "slots" in the rubber. I don't see water will not come out of that hole, especially if the assembly has a water pipe leading up to the weed hatch trunk.

[booke23]

26 minutes ago, Tony Brooks said:

 

I think the seals are in front of the grease hole and the shaft bearing is usually a fluted Cutless rubber bearing with longitudinal "slots" in the rubber. I don't see water will not come out of that hole, especially if the assembly has a water pipe leading up to the weed hatch trunk.

 

Certainly on mine water didn't come out of the grease hole when the screw was removed. I suppose it could depend on the configuration of the water supply hose.....on my boat the intake for it was just above the waterline in the weed hatch so water only went to the gland when the prop was turning. Perhaps the op's intake is below the waterline so the gland is permanently 'wet'.   

Edited March 12 by booke23

[Peanut]

You can get a replacement seal from Vetus, but not cheap. The grease goes in-between the two lips of the seal, also on the shaft, see PDF.

 

https://www.vetus-shop.com/replacement-dual-lip-seal-for-vetus-zwb45-p-2551.html

 

PDF linked on page.

 

[blackrose]

5 hours ago, Tony Brooks said:

 

I think the seals are in front of the grease hole and the shaft bearing is usually a fluted Cutless rubber bearing with longitudinal "slots" in the rubber. I don't see water will not come out of that hole, especially if the assembly has a water pipe leading up to the weed hatch trunk.

 

I've never had water coming out of that screw hole whenever I've removed the screw. However the OP said he was also turning the shaft (at the same time?) so that might do it?

[Tony Brooks]

If brook23 is correct (and I have no reason to believe they are not) then as long as the seal behind the grease void is in good order water can not come up the shaft. It also means that if any water is coming down the breather tube then that should not get into the grease void, so I was wrong.

[blackrose]

12 hours ago, booke23 said:

 

Certainly on mine water didn't come out of the grease hole when the screw was removed. I suppose it could depend on the configuration of the water supply hose.....on my boat the intake for it was just above the waterline in the weed hatch so water only went to the gland when the prop was turning. Perhaps the op's intake is below the waterline so the gland is permanently 'wet'.   

 

After speaking to Vetus some years ago about the non-standard way that these glands are installed on narrowboats, my understanding is that there isn't really a water intake as such and they work on the principle of immersion.

 

If you look at the recommended installation options in the Vetus manual it includes a forward facing underwater scoop hull fitting and a pressurised raw water feed from the engine, so the way they are installed on canal boats is a bit of a fudge but it seems to work nevertheless. 

 

I have the same setup as you with a pipe from just above the waterline in the weedhatch, but I've never been able to work out which way the water is supposed to flow. While moored up without the engine running it's definitely in through the gland, so that pipe acts as a breather releasing any pressure and allowing water into the gland. With the prop spinning and pressure in the weedhatch it may go the other way around as you say.

Edited March 13 by blackrose

[Tony Brooks]

Just now, blackrose said:

 

After speaking to Vetus some years ago about the non-standard way that these glands are installed on narrowboats, my understanding is that there isn't really a water intake as such and they work on the principle of immersion.

 

If you look at the recommended installation options in the Vetus manual is includes a forward facing underwater scoop hull fitting and a pressurised raw water feed so the way they are installed on canal boats is a bit of a fudge but it seems to work nevertheless. 

 

I have the same setup as you with a pipe from just above the waterline in the weedhatch, but I've never been able to work out which way the water is supposed to flow. While moored up without the engine running it's definitely in through the gland and out through the weedhatch, so that pipe acts as a breather, releasing any pressure and allowing water into the gland. With the prop spinning and pressure in the weedhatch it may go the other way around as you say.

 

The same type of bearings are/were used on wooden and GRP boats with a stern tube on the shaft log (keel) and, as you say, they worked by immersion with water "scoops" at the front of the rear bearing housing. If a second bearing was needed, then a bleed type feed from the raw water cooling circuit was fitted. I agree the pipe should act as a breather, but that requires the other end to be above the waterline. If the builder got the height wrong or if the boat has been loaded since fitting, then it might be below the waterline, so could flow through the grease hole if the back seal fails. I suspect that is why the pipe usually has a shut-off valve on it.

[J R ALSOP]

I always was led to believe the fitting on the top of the stern gear was to connect the cooling water outlet from the manifold on the engine.

On old Venus engine / stern gear literature it certainly showed pipe from engine and not stern gear to weed hatch or overboard.

[Drayke]

On 12/03/2024 at 19:01, notts_alan said:

Thank for the input , grease arrived.

Checked prop and no damage , load of rope and fishing net around prop , cleared it all off , no movement on shaft so prop seems fine.

Engine mounts seemed OK,  no unusual vibrations or sounds.

Shaft alignment looks OK.

Shaft couplings and flexible joints all look OK.

Took grease screw out and forced grease in past the jet of water spinning shaft by hand , that slowed the drip right down , ran engine in gear for 5 mins and repacked .

Thankfully now no dripping at all .

I thought about removing the front off buy was not brave enough , I thought water would piss in.

This sounds like you have a damaged seal so you can also expect after a sort while for it to start dripping again, so check on a very regular basis,  When you squeeze in the silicon only put a very small amount in, about the size of a pea. If you put too much into it you can blow the seal out of its housing, been there done that.

There is a thread on here somewhere about these seals, perhaps someone with the know how can point you in the right direction, and even how to replace them with the boat still in the water.  

[robtheplod]

On 12/03/2024 at 20:22, Peanut said:

You can get a replacement seal from Vetus, but not cheap. The grease goes in-between the two lips of the seal, also on the shaft, see PDF.

 

https://www.vetus-shop.com/replacement-dual-lip-seal-for-vetus-zwb45-p-2551.html

 

PDF linked on page.

 

 

wow, that is expensive... Vetus are the Apple of the canal world!

[Tony Brooks]

I would think that it is possible to take the seals out of the housing and replace them with new ones from a local bearing supplier like Bearing Boys. They would need the o.d. & i.d.. However, there would likely be a steady leak into the boat while you are doing the work & getting the new seals.