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Cutlass bearing


Roxylass

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You have now bought  a real  cutless bearing.  It is NOT a direct replacement for the one you had.  The old bearing was grease lubricated.  The rubber one is meant to be water lubricated.  Grease will not improve it and, depending on what sort of rubber it is, may well wreck it in short order.

I would return it and get the right bronze type.

 

The prop shaft is not reversible as it will have a taper at the outboard end, to match the prop.  There are metric tapers  and Imperial tapers.  They are not the same.  I think the metric is 1 in 10 and Imperial is 1 in 12.

 

N

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12 minutes ago, BEngo said:

You have now bought  a real  cutless bearing.  It is NOT a direct replacement for the one you had.  The old bearing was grease lubricated.  The rubber one is meant to be water lubricated.  Grease will not improve it and, depending on what sort of rubber it is, may well wreck it in short order.

I would return it and get the right bronze type.

 

The prop shaft is not reversible as it will have a taper at the outboard end, to match the prop.  There are metric tapers  and Imperial tapers.  They are not the same.  I think the metric is 1 in 10 and Imperial is 1 in 12.

 

N

Agree, its the wrong bearing and apart form the grease potentially wrecking it with water at only one end and no vent/water supply at the other friction from the shaft is also likely to wreck it.

 

In my view not worth fitting, contact Norris

 

If the boat had been fitted out by myself (it has not been) then the shaft might have been reversible because I used a standard Admiralty taper at both ends and a tapered half coupling at the gearbox end. This was far more tolerant to slight shaft out of alignment than the then typical shrunk on shaft half coupling. It also made it far easier to get the gearbox half coupling off compared with shrunk on and allowed the shaft to be reversed but its not the modern way so take heed of @BEngo. Certainly inspect the gearbox end half coupling to see if its clamp on (most likely) or just might be tapered (unlikely).

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12 hours ago, Roxylass said:

Managed to source one from ASAP supplies 

instead of the three grease groves this one has a rubber insert with groves all round 

also been told that the prop shaft could be taken out and reversed 

dont know if there is any truth in this though 

let you know how I get on 

Bear in mind that if you are swapping to this type of bearing you will need to ensure it cannot spin in the tube. On your old bearing there appears to be a notch in the inner end, which I would think locates in an internal pin inside the tube. Normally with cutlass bearings they need grub screws drilled and tapped into the side of the tube to ensure the bearing will not spin.

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3 hours ago, Steve56 said:

Bear in mind that if you are swapping to this type of bearing you will need to ensure it cannot spin in the tube. On your old bearing there appears to be a notch in the inner end, which I would think locates in an internal pin inside the tube. Normally with cutlass bearings they need grub screws drilled and tapped into the side of the tube to ensure the bearing will not spin.

Yes, normal Cutless bearings are secured with grub screws fitted into the sid eof the housing with the bearing body being drilled to form dimples for the grub screws to fit into.

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12 hours ago, Phoenix_V said:

I have had 2 boats with greasy inner and cutlass outer (not my idea) with no apparent problems, if  the op uses the bearing would be a good idea to drill a hole at the forward end to ensure water/venting

Many of our wooden hire cruisers had a plain metal grease lubricated bearing at the front with a Cutless bearing at the back but they had grease caps so it was not  east for a hirer to put so much grease into them it filled the intervening tube and got pushed into the Cutless bearing. They also had water scoops at the front of the Cutless bearing housing so any grease blobs/emulsion that did reach the bearing would get washed through it. The OP's housing has no such scoops and is so short even drilling  through the hosing close to the keel will only be about half way up the Cutless bearing. He can't drill inside the boat because it will sink unless he taps the tube/housing for a vent or water supply tube like Vetus etc. use.

 

I seem to remember that you could specify the type of "rubber" used in the Cutless bearing so maybe (or maybe not) ASAP have supplied a grease tolerant version. (memory may be playing tricks).

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16 hours ago, Roxylass said:

Managed to source one from ASAP supplies 

instead of the three grease groves this one has a rubber insert with groves all round 

also been told that the prop shaft could be taken out and reversed 

dont know if there is any truth in this though 

let you know how I get on 

You couldn't have done that with mine and I doubt if you could do it in many instances The prop end has a thread, taper and keyway.

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9 hours ago, Slim said:

You couldn't have done that with mine and I doubt if you could do it in many instances The prop end has a thread, taper and keyway.

I have come across very few cruisers where this can be done. The gearbox coupling is taper bored and keywayed,  so the shaft can be turned and then run on an unworn part of the shaft.

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50 minutes ago, Steve56 said:

I have come across very few cruisers where this can be done. The gearbox coupling is taper bored and keywayed,  so the shaft can be turned and then run on an unworn part of the shaft.

Both the shaft I replaced and the one I replaced it with had parallel gearbox ends, albeit with a keyway. The original gearbox coupling was parallel bored (R & D type coupling) whilst the Sigma Drive I now have also requires a parallel shaft.  

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10 hours ago, Steve56 said:

I have come across very few cruisers where this can be done. The gearbox coupling is taper bored and keywayed,  so the shaft can be turned and then run on an unworn part of the shaft.

That is because its expensive. two lots of turning and key way cutting on the shaft (we did our own) instead of one plus I never fund a half coupling supplier for read made half couplings that had sufficient counter bore to accept the shaft nut. However struggling to pull a shrunk on coupling off the shaft at god knows where or having one work loose because an engine mount had  failed and the hirer did not notice made that expense worth while.  Half couplings that fit on a taper a the gearbox end form their own puller with the shaft nut partially undone and longer bolts between the two half couplings. However it is not modern practice because clamp on couplings are probably easier to get off. I agree that it will be very unlikely that @Roxylasshas a taper at both ends of the shaft.

Edited by Tony Brooks
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Unless I am mistaken this is a Cheverton workboat. The one we have at our sailing club is the same. The bearing looks OK to me but it could have a bronze or stainless shaft. Maybe a double taper and reversable. Unless the movement between to shaft and the bearing is more than 1mm  I wouldn't be too concerned. If you want to be sure take the shaft out either by removing the half coupling or lifting the engine and sliding out inside. You can check if it is a double taper if it has a nut on the inside end of the half coupling. No nut = parallel shaft. Nut = taper. Quite easy to make up a tool to pull the half coupling off or do what tony says.

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