Leaking volvo stern gland: How worried should I be?

[eddystone]

Only two things to add:
1. Based on my experience changing one a few years ago I cannot imagine how you would do it with the boat in the water
2. I wanted to replace with Radice but the one for 1” shaft wouldn’t stretch over my stern tube

 

[laika]

Good point. I mentioned excessive burping when I greased too far in, probably past all3 seals. Later greasing was aimed at the point between the 2 inner seals which are mainly water lubricated. I also put a bout 1ml just inside the outer seal every second or third year. My logic for that is that this isn't water lubricated and some grease will reduce wear on this final section.

I've never seen any detailed information on this and it would be useful to hear if there's a definitive answer.

Now being in possession of a new volvo seal I'm ready to insert, I'm pondering this. The instructions only say to smear a little grease to aid insertion of the plastic thingy before putting the seal on and to insert the tube of grease and squeeze in 1cc after fitting. But it seems silly to grease after fitting if you can do it before. The marine engineers who sold me the seal said to put grease "liberally" between the two lips. But there are 3 "lips": the outer one then two more flexible inner ones.

Did you conclude that it's the two inner (slanted) lips the liberal pre-installation greasing is applied to? Do others concur, think the space between the outer and outer of the two inner lips should be pre-greased as well , or perhaps that only a light greasing is required?

 

[Mistroma]

Now being in possession of a new volvo seal I'm ready to insert, I'm pondering this. The instructions only say to smear a little grease to aid insertion of the plastic thingy before putting the seal on and to insert the tube of grease and squeeze in 1cc after fitting. But it seems silly to grease after fitting if you can do it before. The marine engineers who sold me the seal said to put grease "liberally" between the two lips. But there are 3 "lips": the outer one then two more flexible inner ones.

Did you conclude that it's the two inner (slanted) lips the liberal pre-installation greasing is applied to? Do others concur, think the space between the outer and outer of the two inner lips should be pre-greased as well , or perhaps that only a light greasing is required?

I had mine installed "professionally" in Spain. I had tried to remove the shaft from the coupling but couldn't shift it. I was going to buy longer bolts, blowtorch and protective matting but decided it was easier to get someone with the correct tools. Bad idea. He turned up when I had cycled to the shower block and my wife let him start. I arrived back to find him starting to hit the coupling with a hammer. I stopped him immediately and we removed it together using his longer bolts, a metal spacer and a blowtorch (exactly what I'd planned myself ). He had installed many of these but did not think it was a bad idea to whack a thrust bearing at 90 degrees with a lump hammer.

I'll cover the rest of the process now that I've given some context regarding his level of expertise. I didn't have any problems with installation from this point onwards.

1) Remove the olds seal, examine the shaft, thoroughly wipe with wet n' dry before wiping and rinsing completely
This meant the shaft was perfectly smooth with no burrs, grit, pieces of metal etc.

2) Apply grease liberally to all three seals. Space between the 2 inner seals and outer seal were all about 50% full of grease.

3) Apply thin smear of grease to shaft and wipe to spread a thin film over all the exposed section.

4) Make certain orange plastic insert is clean and lightly greased before pushing it home over the end of the seal

5) Slide the seal on the shaft and back into position where it can be clamped in the correct position.
I seem to remember that the clamp has a small insert to prevent pinching and ensure more even pressure where the parts of the clamp come together.

6) Pull shaft into position and bolt together loosely before wiggling the orange insertion tool out of the seal.

7) Tighten everything up properly and job done.

I would probably have used a lot less grease but didn't think it was a big deal. I didn't have any problems with the seal after launch and the excess grease did not seem to cause any problems.

I think the important points are cleanliness, no burrs, use orange tool supplied and avoid inverting the seals. Not surprised another "marine engineer" suggests liberal application of grease.

 

[laika]

2) Apply grease liberally to all three seals. Space between the 2 inner seals and outer seal were all about 50% full of grease.

Sorry..to clarify...the inner 2 would be the thin lips which are at an angle rather than perpendicular to the shaft, yes? So is that 50% full grease between those two or between those two *and* between the front of those and the front "lip" (ie the very front of the seal)?

 

[Mistroma]

Sorry..to clarify...the inner 2 would be the thin lips which are at an angle rather than perpendicular to the shaft, yes? So is that 50% full grease between those two or between those two *and* between the front of those and the front "lip" (ie the very front of the seal)?

He didn't take a lot of care, just smeared both grooves with his finger. I guessed about 50%, could have been slightly more or less. As far as I can recall he filled the grooves with grease but did not completely fill right up to the tip of each seal. It didn't seem too unreasonable at the time and I would have objected if he'd fully packed the space with grease. I think the total grease used was still only about 2-3mls.

I seem to remember measuring the internal dimensions of the grooves and estimating they'd take about 1ml each. Seemed to be in line with what I saw. i.e. Grooves filled and some smeared on the lip seals themselves.

I'm pretty certain the amount isn't at all critical as long as you don't try to completely fill the area between the seals. He didn't treat the inner and outer grooves differently wrt greasing.

It was about 6 years ago but I think I'm remembering the details, helped by my notes.

 

[LittleSister]

The old trick with a straw makes it a very quick job, especially if you have a small tube of suitable grease handy (silicone is fine). Just squeeze 1-2 mls

The instructions only say to smear a little grease to aid insertion of the plastic thingy before putting the seal on and to insert the tube of grease and squeeze in 1cc after fitting. But it seems silly to grease after fitting if you can do it before.

I was going to reply to Mistroma's earlier post that my (admittedly slightly hazy) recollection was that the annual greasing was supposed to be 1cc of grease, not 1-2ml.

(I remember calculating how much length of straw needed to be filled with grease to get the required volume, given the internal diameter of the straw. Unfortunately I've forgotten what the length was (about 1.5 cm?), so the calculator will have to come out again for the next annual fill.

It may seem 'silly' to grease it after installation, but presumably there's a reason Volvo specify that. (Perhaps because you would have lost some of the grease as it would be smeared the forward length of the shaft if you'd put it in before installation, and/or you are more likely to get grease on the aft seal which IIRC is water cooled?)

In any case, if you do it once it's installed as specified, you'll at least know exactly what to do when you do your next annual 'service' of it.

 

[Mistroma]

I was going to reply to Mistroma's earlier post that my (admittedly slightly hazy) recollection was that the annual greasing was supposed to be 1cc of grease, not 1-2ml.

(I remember calculating how much length of straw needed to be filled with grease to get the required volume, given the internal diameter of the straw. Unfortunately I've forgotten what the length was (about 1.5 cm?), so the calculator will have to come out again for the next annual fill.

It may seem 'silly' to grease it after installation, but presumably there's a reason Volvo specify that. (Perhaps because you would have lost some of the grease as it would be smeared the forward length of the shaft if you'd put it in before installation, and/or you are more likely to get grease on the aft seal which IIRC is water cooled?)

In any case, if you do it once it's installed as specified, you'll at least know exactly what to do when you do your next annual 'service' of it.

I remember reading the same thing about greasing after assembly. There was also a bit about checking alignment. Pretty certain I'd already pulled the existing one back to check vs. the solid tube and pushed it back into place. I loosened and examined everything I could before the guy arrived, so no delays due to something seized, mis-aligned or missing.

Yes, I also measured the straw to calculate 1ml for the annual greasing. I find that I can reuse the straw a few times before trimming it back and using a new section. I mark the correct length with a marker at regular intervals and just trim to the next mark.

I was pointing out that it the "marine engineer" I used did apply grease prior to fitting as he'd been told by another "marine engineer". I mentioned that the guy I use seemed to have little sympathy for the gearbox bearings. However, he did end up using about 2-3ml including the last seal and some wastage.

I was only changing the seal due to age and it never showed signs of leaking. I had noticed that it needed to be burped every few weeks a couple of years earlier. That was when I decided to try inserting the straw a shorter distance and was only reaching the first chamber. I reverted to the correct distance and the problem vanished. I assume that low pressure in front of the prop. was slowly sucking air in from inside the hull, along the rotating shaft.

 

[LittleSister]

Sorry, brain fade, I'd somehow forgotten 1ml = 1cc.

How did you know it needed burping every few weeks (before you burped it)? I grease before launching, burp after launching, and don't touch it again for the season, so I'd never know.

 

[Mistroma]

Sorry, brain fade, I'd somehow forgotten 1ml = 1cc.

How did you know it needed burping every few weeks (before you burped it)? I grease before launching, burp after launching, and don't touch it again for the season, so I'd never know.

I was fetching something from the aft cabin when sailing and noticed a slight noise from the shaft. I had already burped the seal but it was our first sail soon after launching and more air came out when I burped it again. It seemed reasonable to check again a few days later and a little more air came out. Later checks confirmed that regular burping was needed, mainly after a day or two travelling at 5-6 knots.

I continued the practice of checking after a few long trips at the start of each season. The problem hasn't returned and the only change was to apply the grease in the correct position.

 

[laika]

Thanks for the advice. Boat relaunched today and although the trip to the berth was a short one, the new dripless seal remained dripless, so hurrah!

My old seal's inner lips had completely worn away: it was 11 years old and therefore definitely in need of a change. Ease of change a volvo dripless seal? Easy. With the caveat that removing the shaft from the coupling and re-inserting it was hard and required two fairly strong people, one outside pushing/pulling on the prop. Also with the caveat that figuring out where the grease is supposed to go is not apparent from the instructions, so help here was very useful. Moreover the diagram which says to insert 1cc of grease seems to depict someone just smearing grease from the tube around the shaft *outside* the seal but clearly is not what is required. It's also clear that volvo grease tube's nozzle is not long enough to get grease between the inner lips when inserted from outside.

Now I just need to acquire myself an environmentally unfriendly plastic straw...

 

[Travelling Westerly]

Thanks for the advice. Boat relaunched today and although the trip to the berth was a short one, the new dripless seal remained dripless, so hurrah!

My old seal's inner lips had completely worn away: it was 11 years old and therefore definitely in need of a change. Ease of change a volvo dripless seal? Easy. With the caveat that removing the shaft from the coupling and re-inserting it was hard and required two fairly strong people, one outside pushing/pulling on the prop. Also with the caveat that figuring out where the grease is supposed to go is not apparent from the instructions, so help here was very useful. Moreover the diagram which says to insert 1cc of grease seems to depict someone just smearing grease from the tube around the shaft *outside* the seal but clearly is not what is required. It's also clear that volvo grease tube's nozzle is not long enough to get grease between the inner lips when inserted from outside.

Now I just need to acquire myself an environmentally unfriendly plastic straw...

Sorry for oldish thread resurrection but a search brought this up which is useful to me.

My Volvo seal has just started dripping. Its been fine for the last 3 years of my ownership but I don't know how old the seal is. Saying that I still have the grease and fitment tool but that doesn't give me any idea of age other than there's loads of grease left.

Anyway, lm looking to replace with a Radice seal as I like the grease port and vent tube. The only issue is that I've measured with 2 different calipers and both are showing the shaft diameter is 30.14mm or 1.187 inch! The closest seal size I can find is 30mm. Do you think that a 30.14mm shaft is a 30mm shaft for seal sizing purposes? The current seal must be a 30mm seal as it's a Volvo and I can't see they supply any sizes other than metric?

I've got the stern tube size at 48mm which is bang on for the Radice 30mm model.

 

[Mistroma]

Sorry for oldish thread resurrection but a search brought this up which is useful to me.

My Volvo seal has just started dripping. Its been fine for the last 3 years of my ownership but I don't know how old the seal is. Saying that I still have the grease and fitment tool but that doesn't give me any idea of age other than there's loads of grease left.

Anyway, lm looking to replace with a Radice seal as I like the grease port and vent tube. The only issue is that I've measured with 2 different calipers and both are showing the shaft diameter is 30.14mm or 1.187 inch! The closest seal size I can find is 30mm. Do you think that a 30.14mm shaft is a 30mm shaft for seal sizing purposes? The current seal must be a 30mm seal as it's a Volvo and I can't see they supply any sizes other than metric?

I've got the stern tube size at 48mm which is bang on for the Radice 30mm model.

It will be interesting to hear other opinions. I've never heard of a 1 and 3/16 inch version of the Volvo seal and imagine the seals would easily fit something 30.14mm. It is less than 0.5mm larger in circumference, not exactly much of a stretch (~0.5%).

Pretty certain 30mm version is the correct part.

 

[Bobc]

Sorry for oldish thread resurrection but a search brought this up which is useful to me.

My Volvo seal has just started dripping. Its been fine for the last 3 years of my ownership but I don't know how old the seal is. Saying that I still have the grease and fitment tool but that doesn't give me any idea of age other than there's loads of grease left.

Anyway, lm looking to replace with a Radice seal as I like the grease port and vent tube. The only issue is that I've measured with 2 different calipers and both are showing the shaft diameter is 30.14mm or 1.187 inch! The closest seal size I can find is 30mm. Do you think that a 30.14mm shaft is a 30mm shaft for seal sizing purposes? The current seal must be a 30mm seal as it's a Volvo and I can't see they supply any sizes other than metric?

I've got the stern tube size at 48mm which is bang on for the Radice 30mm model.

Have you never heard of manufacturing tolerances? It's a 30mm shaft.

 

[Travelling Westerly]

Have you never heard of manufacturing tolerances? It's a 30mm shaft.

Umm, not sure if that's a sarky comment or helpful? Maybe both.
I have indeed heard of tolerances but after a lenghty discussion with the local Volvo Penta dealership, he is suggesting that's why the original 30mm Volvo seal is leaking due to it being an incorrect size!
I'm not convinced hence the question!

 

[Clancy Moped]

What diameter is the shaft?

 

[LittleSister]

What diameter is the shaft?

See post no.71

 

[Travelling Westerly]

What diameter is the shaft?

30.14mm or 1 and 3/16 inch.
Can't find any seals at 1&3/16 and Volvo not offering much help. I think 30mm has to be it but wanted to get a general consensus as didn't want to go ahead and fit the new 30mm seal only to find out there was a 1&3/16 inch version available.
It has the same characteristics as Laikas seal did in that the top of seal (12 o'clock position) is in full contact with the shaft but the bottom, 6 o'clock, has a 1-2mm gap, enough to see the inners of the first lip seal?

 

[Clancy Moped]

I'm with the 30mm crowd.

 

[LittleSister]

I think a 30mm Volvo seal will be fine.

If you look at the photo on Vyv's site [ Stern glands ] showing such a seal cut in half lengthways to reveal its innards, the seal lips are diagional (and curved?) in section, and presumably designed like that to flex to accommodate slight variations in shaft diameter, as well as vibration and misalignment.

It has the same characteristics as Laikas seal did in that the top of seal (12 o'clock position) is in full contact with the shaft but the bottom, 6 o'clock, has a 1-2mm gap, enough to see the inners of the first lip seal?

I think that gap at the bottom is just the result of (uneven) wear.

 

[Bobc]

Sorry, not meant to be sarky. 0.14mm is just under 6 thou, which is 3 thou per side. You can't mould in rubber to those tolerances (I would suggest the radice lip seals have a much wider manufacturing tolerance than that (probably +/- 0.2mm).

There is no way that a 3 thou oversize will account for the seal leaking prematurely.