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Cutless Bearing 331


  • This topic has 2 replies, 3 voices, and was last updated 12 years ago by Anonymous.
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  • #552

    Strange noises from under the rear cabin sole. Looked underneath with camera, all appears in place, & nothing wrapped around the prop.

    I suspect that there might be wear in the cutless bearing ?!

    Does anyone have the dimensions and suggested source for a replacement bearing ? I assume that ID (40mm shaft), OD, length are required. What other details are required to get the correct part ?

    Would it be best to go to Siltala for replacement ?

    Anyone got any tips for the removal/replacement ? I believe that there are 2 grub screws located in the P bracket which screw down on the shell of the bearing, these are buried under antifouling.



    I have twice had the cutlass bearing replaced on our 321, but I was never aware of any noise made by it.

    The first time I did it on a precautionary basis because there was a bit
    of play evident in the bearing when inspected on the hard.

    The second time was two years later because the bearing started coming apart – the inner rubber separated from the bronze tube.

    Both times the work was done by professionals, in my case Yachting Sports at Hamble Point who commission new Nauticats.

    I do most of my own maintenance but replacing the bearing is not for the faint hearted in my view.

    I believe YS removed the prop. However rather than then disconnecting
    the prop shaft from the coupler/gearbox and removing it, professionals
    have a tool they put on the shaft and then drive the old bearing out of
    the P bracket using a hammer and brute force. My bracket has one grub
    screw which they removed. Then they drive the new bearing in on the
    reverse basis.

    Bearing are readily available from marine suppliers. I bought the second
    one myself from Aquafax. You just need to know the prop diameter and
    the bearing length. They come in a range of standard sizes. There are
    now composite ones available as well as brass.


    A.S.A.P. Supplies are another supplier –


    Finally se the posting under Boat Jumble and Crew about 331 bearing.


    The information I have was supplied by Richard Bartlett. A company called Countrose ( in Birmingham make all bearings for many boats and I think supply Nauticat. The size bearing for the 331 is 55x40x160mm with a brass casing part No CRM009. Also I believe the same size for the 33 and the 42 possibly others. Speak to Nauticat? They are made of either Nitrile or Polythene rubber. Nitrile is softer and accommodates shaft out of alignment. Polythene is harder and wears much better. Richard said he has used a polythene version for 14 years without any apparent wear. I have obtained one from them and as I live close by went and collected it from the factory. I have yet to fit it but will be doing so soon. Richard also gave me the following info.

    1. Take an old 40mm Dia cutlass bearing and cut it in half long ways.

    2. Cut out the rubber completely.

    3. Clamp the shells onto engine side of shaft with 2 jubilee clips.

    4. Using 2sash type clamps use shells to push cutlass bearing out of P bracket

    If you remove prop first and then reverse the procedure to put new bearing in.

    I hope this is of some help.

    Paul (Dotecom) Marina de Portimao, Portimao, Algarve Portugal.

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