Cutlass bearing

[colin.marshall]

I've taken my colvic countess 28 out because of knocking from prop shaft and sure enough there was huge play and in fact I can't even see leftovers of a cutlass bearing.
I'm looking for help to identify what exactly I need to replace. I now have the shaft out which required me to lift the engine and pull inside boat, due to skeg.
When I felt inside the stern tube I felt a ridge about 3" deep so assumed I was feeling the end of the outer cutlass bearing brass tube and it was the the rubber that had disappeared. Having started to cut it, I now worry I have it wrong and in fact I'm cutting the stern tube since after cleaning up the end I cannot see an outer stern tube and inner tube of cutlass bearing. Hope that makes sense.
From my pictures, can anyone help explain what needs done? Is there an inner brass pipe her, or am I cutting the stern tube here?

 

[alahol2]

That looks suspiciously like a white metal bearing. If it is you need to melt out the white metal.
Having said that, the knurling on the outside of the tube looks like it is intended to be glassed in so maybe that is the actual stern tube and you've not got a bearing carrier at all.
I can't make any suggestions to rectify your problem, sorry.

 

[NormanS]

Cutless bearings come in a fairly standard range of sizes. See if there is a size which corresponds to your shaft diameter and the inside diameter of the stern tube. That might give you a clue.

 

[srm]

If it is a cutless bearing (so called because it cuts or wears the shaft less than a white metal bearing) you will have a bronze shell around three inches long inside the stern tube. The pic does look as if there may be a shell in the tube. There should be one, or two, grub screws in the end of the stern tube to hold the shell in position. These will need removing then ,if you are very lucky, you may be able to pull or tap the shell out. More usual one needs to carefully make a cut right through the length of the the cutless shell so that it can be sprung away from the stern tube and tapped out. However, try not to cut the stern tube - difficult. Basically, it needs the careful application of 'brute force and ignorance' to get it out. Took me the best part of a day after the removal of the shaft.

As said in a previous post you need the diameters of shaft and inside of stern tube to order a replacement. Replacements come in either imperial or metric dimensions. A friend had an imperial tube and metric shaft (or perhaps the other way around), so had to get a bearing to fit the shaft and accept that he has to put up with a loose bearing.

Edit: It does seem odd that there is no trace of the rubber bearing material inside the stern tube/shell. Is there an owners association that may be able to offer guidance?

 

[neil_s]

I don't think that is a Cutless bearing, badly worn or not. There should be water ways to allow for lubrication flow. My 1977 Seal had a white metal bearing - maybe more common for that era?

 

[srm]

How is the stern tube bearing lubricated? White metal bearings are usually oil/grease lubricated, cutless with water.

 

[Shanty]

If you have removed the engine & shaft, you should be able to access the inboard end of the stern tube. Measure it's internal diameter. Compare this with the ID of the outboard end. If they are the same, you are cutting into the shaft tube. Outboard end smaller - you have the shell of some sort of bearing.

Don't forget to check the shaft for wear at the bearing and stern gland areas. Rattling about could have done some damage.

I've taken my colvic countess 28 out because of knocking from prop shaft and sure enough there was huge play and in fact I can't even see leftovers of a cutlass bearing.
I'm looking for help to identify what exactly I need to replace. I now have the shaft out which required me to lift the engine and pull inside boat, due to skeg.
When I felt inside the stern tube I felt a ridge about 3" deep so assumed I was feeling the end of the outer cutlass bearing brass tube and it was the the rubber that had disappeared. Having started to cut it, I now worry I have it wrong and in fact I'm cutting the stern tube since after cleaning up the end I cannot see an outer stern tube and inner tube of cutlass bearing. Hope that makes sense.
From my pictures, can anyone help explain what needs done? Is there an inner brass pipe her, or am I cutting the stern tube here?

 

[vyv_cox]

There are photos and information about similar arrangements on my website at Stern gear

 

[smithy]

If you think it might be a shell in there why not make up an extractor using a couple of sockets and some threaded bar? This presumes that there is no inner bearing and you can push a socket down the tube. at least that way you wont damage anything.

 

[LadyInBed]

There must be a good reason, but I can't think of it, why cutless bearings are not fitted with say a half inch protruding from the end, so that they can be extracted easier.

 

[SlowlyButSurely]

There must be a good reason, but I can't think of it, why cutless bearings are not fitted with say a half inch protruding from the end, so that they can be extracted easier.

I always fit them on my boat protruding by about a quarter of an inch for that reason, but if it were any more than that it would not be possible to get the prop puller on the remove the prop.

 

[NormanS]

I always fit them on my boat protruding by about a quarter of an inch for that reason, but if it were any more than that it would not be possible to get the prop puller on the remove the prop.

I don't know why all propellers don't have tapped holes on their aft faces. It makes removal so simple.

 

[colin.marshall]

If it is a cutless bearing (so called because it cuts or wears the shaft less than a white metal bearing) you will have a bronze shell around three inches long inside the stern tube. The pic does look as if there may be a shell in the tube. There should be one, or two, grub screws in the end of the stern tube to hold the shell in position. These will need removing then ,if you are very lucky, you may be able to pull or tap the shell out. More usual one needs to carefully make a cut right through the length of the the cutless shell so that it can be sprung away from the stern tube and tapped out. However, try not to cut the stern tube - difficult. Basically, it needs the careful application of 'brute force and ignorance' to get it out. Took me the best part of a day after the removal of the shaft.

As said in a previous post you need the diameters of shaft and inside of stern tube to order a replacement. Replacements come in either imperial or metric dimensions. A friend had an imperial tube and metric shaft (or perhaps the other way around), so had to get a bearing to fit the shaft and accept that he has to put up with a loose bearing.

Edit: It does seem odd that there is no trace of the rubber bearing material inside the stern tube/shell. Is there an owners association that may be able to offer guidance?

Thanks for advice. It doesn't seem like there are many of these boats about so struggling to find anything.
It makes sense that there is a cutlass bearing with an outer sleeve but I have no idea why there's no sign of rubber component or why I can't see a ring on outer end which would make me feel I have something to knock out. Also cannot see signs of a grub screw.
The reason I started cutting was that I thought the fact I could feel the ridge of where the outer end got smaller meant there was an Insert. Then when I couldn't see an obvious ring I became unsure.

 

[srm]

Then when I couldn't see an obvious ring I became unsure.

Its always a bit worrying when trying to solve a boat problem first time around.
All I can suggest now is accurately measuring the inside diameter of the stern tube at both inboard and outboard ends with calipers. Any difference in diameters should indicate if there is a bearing shell still in there. You then have to decide what type of bearing it was for a replacement. As I suggested earlier the type of lubrication fitted should be an indication (though I suspect that one of my boats had a rubber cutless bearing, possibly as a replacement for white metal, though the shaft was oil lubricated). Fortunately, I never had to remove the bearing and find out.
The absence of a stern tube greaser strongly indicates it had a cutless bearing, though if you have a traditional packed stern gland that will require grease and may have been used with a cutless bearing. Many possible permutations!!

 

[colin.marshall]

I do have a greased stern gland too. After Christmas I will get another look at both ends. I'm going to remove the fuel tank which is hindering access inboard. Of course there's a season approaching, covid permitting, so I want to move forward quickly.

 

[colin.marshall]

I've taken my colvic countess 28 out because of knocking from prop shaft and sure enough there was huge play and in fact I can't even see leftovers of a cutlass bearing.
I'm looking for help to identify what exactly I need to replace. I now have the shaft out which required me to lift the engine and pull inside boat, due to skeg.
When I felt inside the stern tube I felt a ridge about 3" deep so assumed I was feeling the end of the outer cutlass bearing brass tube and it was the the rubber that had disappeared. Having started to cut it, I now worry I have it wrong and in fact I'm cutting the stern tube since after cleaning up the end I cannot see an outer stern tube and inner tube of cutlass bearing. Hope that makes sense.
From my pictures, can anyone help explain what needs done? Is there an inner brass pipe her, or am I cutting the stern tube here?

Some further Information on this, to add to images. I am still trying to work out what I need to buy, and whether I have an insert still there that needs removed....
Shaft Dim is 1" (25.4mm)
outer dim for stern tube is approx 44.4mm
Inner dim is 33mm
That makes wall of stern tube about 5.7mm thick for about 75mm from prop end before it reduces by an unknown amount.

 

[srm]

Some further Information on this, to add to images. I am still trying to work out what I need to buy, and whether I have an insert still there that needs removed....
Shaft Dim is 1" (25.4mm)
outer dim for stern tube is approx 44.4mm
Inner dim is 33mm
That makes wall of stern tube about 5.7mm thick for about 75mm from prop end before it reduces by an unknown amount.

Colin,
Shaft is one inch, so stern tube is probably imperial and you will need the internal diameter to order a new bearing. The 75 mm is around the right length for a cutless bearing, however, just under 4mm thickness for the rubber bearing, which will have shallow grooves for the water flow may be a bit thin. It is over two years since I removed a cutless bearing for a slightly larger shaft so my memory of the proportions may be adrift.

Three ideas:
- look at the cutless bearings on boats hauled out with 1 inch shafts and see if the dimensions match yours.

- find a marine engineer with experience of yachts and ask their advice.

- if you have not already done so an internet search will give overall cutless bearing dimensions, ie:

Standard Imperial Brass Shelled Cutless Bearings

An email to a supplier explaining your problem and asking for thickness of shell and bearing material for your one inch shaft may confirm you dimensions.

In the meantime you could try removing the shell/insert, as a stern tube is normally a constant internal diameter. (see my earlier post for removal).

 

[Tranona]

Standard cutless for 1" shafts (double check it is not 25mm!) have outer shells of 1 1/4", 1 3/8" or 1 1/2" all 4" long so I don't think your tube had a cutless. Best to talk to h4marine.com about having a composite bearing made exactly to fit your tube and shaft.

 

[colin.marshall]

Thanks for feedback. It could very well be 25mm so I will double check. I also need to check for wear too on shaft. I thought it was very strange that if it was a cutless bearing that was previously there, why nothing left of the inner part of it. I didn't actually think there was so many arrangements until I started reading up etc.
I cannot see a grub screw or anything that would hold a bearing/shell in place. Could it be a press or tapered fitting of some sort? I will follow you method to try remove it without further cutting.
I am also wondering if that is not the outer shell of a bearing, might have the shaft worn it to a greater diameter than it once was.

Last question, is it an option to just get a cutless bearing made to the measured sizes and then just press it in there? Could I then drill/tap for a couple of grub screws?

 

[alahol2]

...Last question, is it an option to just get a cutless bearing made to the measured sizes and then just press it in there? Could I then drill/tap for a couple of grub screws?

If you can find one that's a fairly close fit (eg 1" x 1 1/4") you can glue it in with epoxy. That's how mine is done. The epoxy can be softened with heat to remove it in future.