Anybody Familiar with this type of Stern Tube?

[Arisaig]

So I have not seen this type of set up for the stern tube and bearing. The cutlass bearing kinda floats in the stern tube with a large rubber washer to stop water intrusion. Do I just replace the bearing with a standard cutlass bearing and slide the rubber seal on the outside or do I need a special cutlass bearing? the wall of the cutlass seems thicker than others I have replaced before. Any advice would be much appreciated

https://www.cruisersforum.com/galler...?i=14158&c=500

[skipperpete]

Is your sterntube oil filled? Excluding water from a conventional fluted rubber stern bearing( cutlass) would quickly destroy it and cause the inboard shaft seal to overheat if run dry. Look inside the boat for an oil reservoir with a pipe leading to the stern gland.

[coopec43]

What sort of seal do you have - a stuffing box or mechanical seal (Tides Marine, PSS, Dripless etc)?

[Arisaig]

It is a stuffing box on the inside. no oil reservoir. this is what I would take to be the cutlass but it basically floats inside the housing. This is 1971 Finnish boat so I assume that when the rubber gasket was new it was much tighter where it goes into the stern tube. basically when you pull the two screws this is inside the housing. the gasket is tight on the bearing and fairly tight in the stern while allowing some movement. It looks like there was the typical rubber inside the "Cutlass Bearing" but it is fried from 50 years of use. I just bought the boat a few months ago and am refurbing it.

https://www.cruisersforum.com/gallery/showimage.php?i=14158[/IMG]

[Arisaig]

[coopec43]

You've lost me. What are the photos of?

https://www.cruisersforum.com/gallery/showimage.php?i=14158[/IMG]

What is the make of your yacht (We know it is a 1971 Finnish boat). If we knew that it might help sort out the riddle.

[Arisaig]

Sorry It is a Nordic 26 Motorsailer. I could not get the site to post the photo the photo of what I assume to be the cutlass bearing. for some reason I paste in the URL which is below but it does not show the photo. If you copy and paste the link below it is the bearing and seal I refereed to in my post above. So this is inside the shaft log with the big rubber washer.
https://www.cruisersforum.com/galler...ge.php?i=14158




[/IMG]

[coopec43]

Is this the boat?

https://dailyboats.com/boat/38985-buy-nordic-81


https://essex.boatshed.com/nordic_81...oat-31523.html


Well I'm not really getting anywhere. I thought there might be an owners' forum but can't see one.


There is a link at the bottom of this page.

https://www.luxuryatch.com/1973-nordic-8-1/

[mlydon]

If the rubber bit clamps the cutlass only, and doesn’t allow it to spin, I think you’re golden. Sounds like the cutlass is rubber-supported. The cutlass should extend past the rubber though - no seal - water is needed to lube the cutlass/shaft. Better pics of it open would be nice.

I’ve seen similar, bolted on cutlass holders, notably on an old port motor launch, the had setscews to hold the cutlass in place.

I think you need to watch out for the rubber being hard - it doesn’t last forever, and god knows if you could get a replacement

Matt

[Uncle Bob]

Originally Posted by mlydon

If the rubber bit clamps the cutlass only, and doesn’t allow it to spin, I think you’re golden. Sounds like the cutlass is rubber-supported. The cutlass should extend past the rubber though - no seal - water is needed to lube the cutlass/shaft. Better pics of it open would be nice.

I’ve seen similar, bolted on cutlass holders, notably on an old port motor launch, the had setscews to hold the cutlass in place.

I think you need to watch out for the rubber being hard - it doesn’t last forever, and god knows if you could get a replacement

Matt

My wild assed guess would be that the shaped rubber bush holds the cutlass bearing in such a way that it is effectively self aligning.

[Arisaig]

Yes Coopec43 that is the boat type. Myldon and Uncle Bob you are I think spot on. I am concerned that the rubber bit is old and stiff and short of having one made I don't think I could replace it. I was thinking of reinstalling it with a bead of 4600 on either side to tighten tighten the fit a bit accepting that if I take it out again it will need a replacement if I have to grow a rubber tree and fab it myself! we do have a custom gasket shop in town but without the original specs it would be a crap shoot.
Thanks for the info and advice. If I cant get it off the old bearing I will have to have on fabed anyway.

[boatpoker]

Or ....... just replace it with a more conventional shaft log.
Not that expensive and makes future cutless changes a breeze.

https://www.ebay.ca/itm/Rinker-Buck-.../193350113085?

[jimbunyard]

Could be a Stuart Turner shaft log; as you've deduced the rubber gland probably seals the cutlass bearing into the internal, forward part of the shaft log; the outboard bearing housing squeezes the rubber gland seal into the mating recess in the forward housing and around the cutlass brg, just like the brass ring around a copper tube in a common water-supply compression fitting under your kitchen sink.

If you can't find the original supplier, an appropriately-sized bronze/rubber cutlass brg should be available and the OD could be machined a little oversize to tighten up the fit a little bit, provided the rubber in the existing gland hasn't hardened.

In that location it is possible that the original is still OK, as it is protected from both oxygen and UV, in that application the rubber should probably be pretty hard new from the factory.

[Arisaig]

You are spot on jimbunyard. I pulled it today and it has the extrusion on the bearing exactly as you describe. The rubber is in great shape. I cannot find a bearing with the extrusion so I am thinking I can use a thick walled standard Johnson's cutlass slightly over sized on the OD and have an extrusion made and fixed to the OD at a local shop.
Changing the stern tube would be a major PITA Boatpoker, It extends 18" inside the boat through the thick glass in the stern in an inaccessible area to a bulkhead where it is flanged to bolt to an intermediate bearing and the packing gland.

[Arisaig]

Image attached