Problem replacing stuffing box with a modern seal

A compromise between taking it off for machining and going at it in place with a hacksaw might be just to buzz the lip off with a belt file/finger sander. Slow and steady. Little chance of catastrophic damage to boat or fingers! And you’d probably need one to make good the grinder/saw job anyway.
 
anpgr said:
Very helpful advice here! Thank you all - I do appreciate it.



I did in fact have more questions regarding stern gear but didn't want to bombard you with these in one thread. The boat is a long keel Halcyon 27 - engine is Bukh DV10. Not sure about the stern tube itself, but have attached some photos of stern outboard bronze fitting where a cutless would normally sit. Here I have what appears to be a solid bronze bearing inside the stern fitting. I will attempt to replace this bearing as it is slightly pitted inside and since I'm getting a new prop shaft I'd rather change everything. - but not sure it can be removed - depending on seal choice, I may replace with cutless. Have asked a local professional to help me out next week. The stuffing box was a traditional grease lubricated one - shown in photo before I removed everything. Also some more pics of inboard fitting. The stern tube can be seen behind the small bulkhead where the inboard fitting is mounted.

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Much clearer now. That stuffing box mounting is really horrible!

Suggest you bite the bullet and remove both housings from the stern tube. Have the inboard end machined to take a Radice seal. Are you sure the original shaft is 25mm rather than 1"? Important you get it right and don't change from the original as the coupling on the engine will only take the same size as the original - the 0.4mm difference is critical. a 25mm is smaller than 1" and will be loose in the clamp!

For the aft end, hopefully that old bearing will push out - may need a press. Choice for replacement. A cutless would be easiest but you may not find a standard size with the right OD. Alternatively you could have a composite bearing made to fit which you can epoxy in. h4marine.com is a good source using Maritex.

Cannot stress more how important it is that the gearbox coupling, inboard seal and outboard bearing must all be the same size as the shaft and the taper to match your prop. Found out the hard way when a machinist made a mistake and fitted a 25mm cutless for a 1" shaft "might be a bit stiff" but caused endless head scratching until removed and mistake discovered.

when refitting the housings suggest you use a polysulphide sealant such as arbokol and you may need to replace the locking screws.

Good luck.
 
The photos do indeed make it all much easier to understand. You should firstly realise that the inner and outer bronze bearings rely on grease to lubricate them - the grease coming from the greaser on the stuffing box. If you just replace the stuffing box with a Volvo/Radice style seal, there'll be no grease for the bronze bearings. So you'd need to remove the bronze bearings.

If you replace the outer bronze bearing with a cutless bearing, it won't have proper water lubrication. Housings for cutless bearings have water scoops at the forward end. So you'd need to replace the outer bearing housing too.

I'd be tempted to service the stuffing box and re-fit it using a new piece of hose.
 
hi, before you start making alterations to your stern tube you might be interested in my experience. I have a very similar arrangement to yours which is also very hard to get at. When I bought the boat it had a Halyard deep sea seal fitted which soon failed. When this was removed I was left with the stern tube part of the original stuffing box with a lip similar to yours. Because I needed to do something quickly I decided to fit a Tides Marine dripless seal, I don't recall any problem fitting this over the lip as the "rubber" part is not very thick and is quite flexible. I would have used a bit of washup liquid as a lube. However, I have now changed back to a traditional stuffing box. On my previous boat I had a Volvo seal, which was excellent but needed to "burped" on relaunch, so may be a problem if the access is not good.

Can't seem to upload the photo but if you pm me I might be able to send it.
 
My father owned a Halcyon 27 from new back in the 60s, and the original engine fitted was a Sabb 8hp diesel. This used a variable pitch propeller instead of a gearbox; the original shaft would have been an outer tube with an inner shaft; relative motion between the two changed the pitch of the propeller - see page 11 of this: http://www.varen4u.nl/pdfs/sabb/SABB-service-and-maintanence-tips.pdf

From your photos, it looks to me very much as if the stern fitting is original; part 12 on the diagram on page 11 of the above. Now, I'm not absolutely certain of this, but it looks to me as if that part is actually a thrust block; there are certainly things going on behind what you can see.
 
AntarcticPilot said:
My father owned a Halcyon 27 from new back in the 60s, and the original engine fitted was a Sabb 8hp diesel. This used a variable pitch propeller instead of a gearbox; the original shaft would have been an outer tube with an inner shaft; relative motion between the two changed the pitch of the propeller - see page 11 of this: http://www.varen4u.nl/pdfs/sabb/SABB-service-and-maintanence-tips.pdf

From your photos, it looks to me very much as if the stern fitting is original; part 12 on the diagram on page 11 of the above. Now, I'm not absolutely certain of this, but it looks to me as if that part is actually a thrust block; there are certainly things going on behind what you can see.
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What an astonishingly complicated system!
 
pvb said:
But gearboxes rarely go wrong (cue numerous posts claiming the opposite!). As for complexity, that Sabb system takes some beating.
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True. Actually, it did have a couple of advantages. First, it was continuously variable, so theoretically, you could select the ideal pitch for the revs being used. Second, you could align the propeller blades fore and aft, minimizing drag under sail (I think that was a special modification, but it's on the manual I posted.
 
I would ask this question directly to PYIinc.com - they make the PSS seal.

The recess depth is 3mm, not 6mm, and the jubilee clamps on the PSS seal are quite powerful, however, they also supply inner sleeves to adjust the range of their seals. Hence it might be possible to use one of these to sit past the 51mm diameter section.
 
When I replaced the original stuffing box with a Radice, I had a new fitting made with the correct diameter for the Radice seal. A firm on the Broads made it for me at a reasonable cost.
 
Once again, thanks for the advice. I have asked a professional to come and discuss options so will probably have a better idea in a few days. What was meant to be a quick antifoul job has turned into major works - looking to go back into the water soon so that will certainly influence my choices.

pvb said:
I'd be tempted to service the stuffing box and re-fit it using a new piece of hose.
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I am indeed tempted to service & re-install my stuffing box .

vyv_cox said:
You can view similar arrangements and some solutions on my website at Stern gear
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I have consulted your website on numerous occasions - I don't know how I missed this page.

Tranona said:
Are you sure the original shaft is 25mm rather than 1"? Important you get it right and don't change from the original as the coupling on the engine will only take the same size as the original - the 0.4mm difference is critical. a 25mm is smaller than 1" and will be loose in the clamp!

when refitting the housings suggest you use a polysulphide sealant such as arbokol and you may need to replace the locking screws.
Click to expand...

Certainly 25mm - just had new prop & shaft made by T.Norris (great service by the way).
Is Arbokol 1000 a good substitute for Sika 291i

AntarcticPilot said:
From your photos, it looks to me very much as if the stern fitting is original; part 12 on the diagram on page 11 of the above. Now, I'm not absolutely certain of this, but it looks to me as if that part is actually a thrust block; there are certainly things going on behind what you can see.
Click to expand...

I don't think that's the case but will certainly have a better idea in a couple of days when this is removed.

pawl said:
hi, before you start making alterations to your stern tube you might be interested in my experience. I have a very similar arrangement to yours which is also very hard to get at. When I bought the boat it had a Halyard deep sea seal fitted which soon failed. When this was removed I was left with the stern tube part of the original stuffing box with a lip similar to yours. Because I needed to do something quickly I decided to fit a Tides Marine dripless seal, I don't recall any problem fitting this over the lip as the "rubber" part is not very thick and is quite flexible. I would have used a bit of washup liquid as a lube. However, I have now changed back to a traditional stuffing box. On my previous boat I had a Volvo seal, which was excellent but needed to "burped" on relaunch, so may be a problem if the access is not good.
Click to expand...

This was what I originally planned to do but having read all the opinions here I am skeptical - why did you go back to a traditional stuffing box?
 
anpgr said:
Once again, thanks for the advice. I have asked a professional to come and discuss options so will probably have a better idea in a few days. What was meant to be a quick antifoul job has turned into major works - looking to go back into the water soon so that will certainly influence my choices.
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Please let us know what you decide, and how it works out in operation.
 
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