I need to replace the cutless bearing on Black Jack a Baker built Seal. Looking through the forum it sounds as though it's similar to the Seal 28. It has a flange at the back with two bolts. Just wondered if anybody has any experience of accomplishing this.

Paul, I just replaced (in all honesty, had an engineer do it) my bearing in a Super Seal 26. Sounds like it could be the same setup as yours. My bearing was indeed threaded to a flange, which had a total of 4 holes in it: 2 to bolt onto the hull and 2 to attach bolts to pull it out with bearing attached to it.

The bearing was threaded onto the flange, but as the flange is only about 5mm thick, the bearing had unthreaded itself and was loose inside the hull. My hull had about 2mm of extra space on each side when bearing was centered. The marine engineer I hired to change my bearing said he has never in his 20 years in the business seen such a setup - but then admitted it is genius: The usual ‘tight fit’ of cutlass bearing to hull means the only way to change one is to saw it off - in my super seal you can just pull it off using the two holes in the flange (as long as the bearing is still on the threads...).

The solution: we manufactured a longer flange, of ‘top hat’ shape: The outer bit has same dimensions, but then continues inside the hull about 1/3 of the cutlass bearing length. It ensures tight fit between cutlass bearing and the hull, and is threaded all the way. This way the bearing is threaded 1/3 of its length and has no chance to unthread itself anymore due to engine vibration. Off the shelf bearings are never threaded, so needs to be done - takes a lot of force I heard.

A bit difficult to explain without pictures, but happy to epand further if you’d like to!

Hi. I think I understand. Does that mean you can remove it by just taking the prop off and leaving the shaft in place. Not sure what you mean by the two bolts to pull it out. Do you mean they are threaded holes in the flange, so if you screw bolts in it seperates the flange from the hull and therefore pulls the bearing out of the tube, as long as the bearing is still screwed into the flange. Cheers Paul

Yes exactly: take the prop off, unscrew the flange from hull and use the threaded holes to pull it out with bearing attached to it. Shaft can be left in place. Even if the bearing has unthreaded itself, you should be able to pull it out, as it is not tightly fitted against the hull. All this of course providing that it is the same construction as mine. Good luck!

Thank you. That is very helpful. I'll have a go when the boats lifted out at the end of the season, unless it has to be done earlier. I've never noticed the other two threaded holes so that might of been added on later models.
Regards Paul