Cutless bearing housing removal

[skirmisher]

I am renewing the cutless bearing on my Rustler 36 this winter, as the grumbling from the shaft was becoming louder as the season progressed, as was the water ingress from the stern gland. The cutless bearing housing in the propeller aperture is secured with two bolts through the hull, with nuts (just about) accessible from within the boat. After removing these, I was hoping the cutless bearing support would then pull free, but it doesn’t want to budge.

I wondered if anybody was able to identify this shaft log and could advise how it might come apart. It is different to many designs in that it has water scoops forward of the bearing. I also cannot see any set screws holding in the cutless bearing either so I assume this is a press fit into the housing, but that may reveral itself when I've got it on the bench.



Many thanks,

David

 

[pete]

I did one like that for a friend, as well as the two bolts the cutless housing was also screwed on to the stern tube in his case.

Pete

 

[Tammany]

Pete got their first. The 2 parts are screwed together, if you are lucky it will free without ripping out the tube inside the boat too.

 

[vyv_cox]

There are photos of two examples of this arrangement on my website at https://coxengineering.sharepoint.com/Pages/Sterngear.aspx. bottom of the page.

 

[skirmisher]

Thanks to the help above I got the carrier off without any fuss – a three-foot pair of Stilsons made short work of it and the set screws holding in the bearing were eventually located under many years’ worth of antifouling. Many thanks to those who replied for the advice.

After it all came apart, I was surprised to find that the shaft log is not glassed into the boat at the aft end. The stern tube appears to only be fixed to the boat by virtue of the fact the two threaded end pieces (i.e. the cutless bearing carrier and the stuffing box aft end) are bolted to the hull. I'm still pondering what to do here, as filling the relatively small voids and glassing it in will be tricky (access inside is so poor to clean/key the area) and may also hamper future attempts to remove the bearing carrier.

I would be interested to hear opinions on this - with all the bolts done up the stern tube isn't going anywhere, but should it be glassed in or will a suitable sealant suffice?

 

[Tranona]

Bed the housing down with plenty of a non setting sealant such as a polysulphide. I also put a ring of caulking cotton in the gap. Never had any problems with getting it apart again or leaks.

 

[alahol2]

Yes, mine is very similar. Sealant has been working OK for the last 6 years or so.

 

[ghostlymoron]

I wouldn't glass it in as that will make it almost impossible to remove in future. The arrangement you have prevents any ingress of water and is dismantleable. It's a very common and well proven design and doesn't rely on a bit of rubber tube at the gland end.

 

[skirmisher]

Thank you all for your replies, I’m glad what I’ve got isn’t out of the ordinary. My last boat, a Halcyon 27 which I owned for over 25 years, had a very different arrangement – the tube was firmly glassed in and replacement would have involved some serious surgery. It had a greased white metal bearing at each end, so cutless bearings are new to me. Needless to say I never had to do anything to it – even when I changed the engine in 2010, there was no wear on the shaft whatsoever.

Incidentally ghostlymoron, I do rely on a rubber tube to keep me afloat – the forward end of the tube screws onto the aft end of the gland seal, onto which a rubber tube is clamped. Here’s a photo of it with the rubber tube removed:

 

[ghostlymoron]

In that case, I would change the inboard fitting for one that screws onto the stern tube and also screws onto the stern log. It's usual to have two out of the three fixed points with a degree of flexibility. The cutlass bearing counts as one so a flexible coupling such as an R and D should be fitted at the engine end.

 

[skirmisher]

I remember seeing that rule of thumb when I re-engined my Halcyon 27. I interpreted it differently, in that the three 'items' were the engine beds, coupling and shaft. In my case with the Halcyon, I had a shaft with no degree of flexibility at either end and the old engine bolted directly to the bed without any rubber mounts. To fit the new engine with its swish rubber mounts, I needed a flexible coupling to allow it to move relative to the shaft. With the Rustler, I have flexible engine mounts and a shaft with a cutless bearing (i..e mobile), so I consider those to be my two flexible parts (I therefore have a fixed shaft coupling) and my stuffing box with its wobble joint rubber tube type arrangement to be part of the shaft.

 

[vyv_cox]

I remember seeing that rule of thumb when I re-engined my Halcyon 27. I interpreted it differently, in that the three 'items' were the engine beds, coupling and shaft. In my case with the Halcyon, I had a shaft with no degree of flexibility at either end and the old engine bolted directly to the bed without any rubber mounts. To fit the new engine with its swish rubber mounts, I needed a flexible coupling to allow it to move relative to the shaft. With the Rustler, I have flexible engine mounts and a shaft with a cutless bearing (i..e mobile), so I consider those to be my two flexible parts (I therefore have a fixed shaft coupling) and my stuffing box with its wobble joint rubber tube type arrangement to be part of the shaft.

That is close to my understanding: the third flexible is the cutless bearing. I have tried to explain it in the first couple of paragraphs of this page https://coxengineering.sharepoint.com/Pages/Sterngear.aspx