Stern Tube & Cutlass Bearing question

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Sea badger

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Hello. I'm renovating a Contessa 26, and have removed the prop shaft to check its ok, as it was little stiff. The stern tube "cooling / lube" openings in the stern tube are bit blocked. But I'm not certain how far the channel goes towards the stern tube. I'm actually thinking of taking it out as it feels a little loose. But does anyone recognise the make of the stern tube / cutlass bearing assembly?? I can't see any name on any of it. It seems to be bronze. I would like to know what it all should look like, for when I clean it up and re-assemble it. Thanks.
 

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Once you take those locking screws out it will unscrew from the stern tube, although it may need a big stilson to get it moving. If the assembly is loose it may be that the whole stern tube is loose. Have a look at the inboard end to see how it is located. The ears are to increase water flow, but there should be enough getting in provided there is a gap in front of the prop. Worth talking to Jeremy Rogers about the actual construction before wading in.
 
Tranona said:
Once you take those locking screws out it will unscrew from the stern tube, although it may need a big stilson to get it moving. If the assembly is loose it may be that the whole stern tube is loose. Have a look at the inboard end to see how it is located. The ears are to increase water flow, but there should be enough getting in provided there is a gap in front of the prop. Worth talking to Jeremy Rogers about the actual construction before wading in.
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Thanks for reply. This is the view from inside; looking astern, do you think that's the join where it unscrews from? thanks
 
No. It unscrew from the outboard end. My concern is that if the stern tube is not solidly located where it goes through the keel you may disturb the whole assembly.
 
Tranona said:
No. It unscrew from the outboard end. My concern is that if the stern tube is not solidly located where it goes through the keel you may disturb the whole assembly.
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Yes I see what you mean. In the photo above there is a small flange at the top of the tube, which is bolted to the hull. no movement here, the end of the tube towards the bow, goes through a small bulkhead and should be bolted here, but the bolt is missing. So I will re-bolt this to ensure no movement. slight movement I feel on the outboard side may be sealant movement? But I'm a bit stuck as I need to get the tube out to clear the water passages that are blocked. Unless I'm missing something?
 
You should not need to remove it to clear those passages. Poke around from outside. They only go in a short way. The main reason for removing the whole housing is to replace the cutless bearing inside. The housing should be bedded down on sealer, preferably Polysulphide and to replace you screw in until it beds on the sealer and the locking holes line up. that sealer may have broken down over the years. If the other end of the tube is fixed it should be straightforward if hard work to unscrew the outer housing.
 
It does look similar to mine in Vyv's link.
Not wise IMO to remove the nuts you have your spanner on in your 1st pic, you never know what is going to fall off / twist and not be able to retighten on the inside!
Undoing the smaller nuts and bolts on the outer end should allow you to remove the end fitting, then after removing the grub screw, get some mole grips on the exposed inch or so of bearing to twist it out.
 
LadyInBed said:
It does look similar to mine in Vyv's link.
Not wise IMO to remove the nuts you have your spanner on in your 1st pic, you never know what is going to fall off / twist and not be able to retighten on the inside!
Undoing the smaller nuts and bolts on the outer end should allow you to remove the end fitting, then after removing the grub screw, get some mole grips on the exposed inch or so of bearing to twist it out.
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Thanks for replies. Do you know if the two studs that we have removed the nuts from, go through the hull, or and embedded in from the outside?
 
Tranona said:
You should not need to remove it to clear those passages. Poke around from outside. They only go in a short way. The main reason for removing the whole housing is to replace the cutless bearing inside. The housing should be bedded down on sealer, preferably Polysulphide and to replace you screw in until it beds on the sealer and the locking holes line up. that sealer may have broken down over the years. If the other end of the tube is fixed it should be straightforward if hard work to unscrew the outer housing.
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I thought the passages go the full length of the cutlass bearing and all water to be drawing into the cutlass bearing, which would then be ejected out of the cutlass bearing via the grooves. But I'm new to this and there isn't a lot of fundamental info on the web, or good books. If you know of any let me know. thanks.
 
When the boat goes in the water the stern tube fills up to the inboard seal. The water passages re extra and useful with high speed or high hp applications. However they easily get blocked with marine life and silt.

Looking more closely at your photos perhaps I was wrong in saying the outer housing would unscrew. Suspect the studs or bolts go right through and hold a similar flange inside the boat. In which case ensure those screws do not move. The outer housing will pull off rather than unscrew.
 
Tranona said:
When the boat goes in the water the stern tube fills up to the inboard seal. The water passages re extra and useful with high speed or high hp applications. However they easily get blocked with marine life and silt.

Looking more closely at your photos perhaps I was wrong in saying the outer housing would unscrew. Suspect the studs or bolts go right through and hold a similar flange inside the boat. In which case ensure those screws do not move. The outer housing will pull off rather than unscrew.
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thanks, will have a closer look.
 
Just looked at 2 Contessa 26s today and both have very different bearing housings to yours. They are the small screw on types I mentioned and assumed yours would be. so clearly they fitted different types over the production run.
 
Blocked passages.jpg

I'm struggling to find out if the water passage, that is blocked in the photo, goes all the way to the stern tube, and if the water then gets "sucked out" of the cutlass bearing? If it doesn't I can leave the cutlass bearing in place, and just "pick out" the water passage as much as possible.
 
These things vary a great deal - but on mine the stern tube is screwed in both ends - into the outer housing and into the stuffing box unit. The outer housing is often bolted through the grp - but the heads can be glassed over or obscrured through debris.
You may have to remove the inner flange securing bolts and then the stern tube will unscrew from the outer.
You can then access the bolt head below the stern tube.

As I say - they vary, but thats how mine is set up.
 
Sea badger said:
Thanks for replies. Do you know if the two studs that we have removed the nuts from, go through the hull, or and embedded in from the outside?
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They are normally bolts through the hull. If your lucky they are glassed in on the head so they don't twist when you tighten the nuts.
The waterway is up the slots in the rubber bearing.
Have you found the grub screw underneath the assembly that holds the bearing in yet?
 
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