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Post by robinwr on May 17, 2012 12:39:56 GMT
Hi - I'd noticed that I was getting a small bit of vibration when sailing (we have a fixed three blade prop and leave the gearbox in neutral) and when motoring at 2500+ rpm. By small I mean small which only the OCD types would notice.
She is now out of the water and there is a bit of play in the cutless bearing - some have said it's not too bad and not to worry and others have said change it.
I tried last night to remove it with the shaft in place using a homemade removal tool to pull the bearing out but it's stuck tight.
Do these tend to be difficult to remove.
Anyone know what size to replace it with - I got a 30 x 45 x 120 but I think the O/D is less than 45 and the overall length is more than 120 (~130)
The shaft is 30mm and I think that it could be a mix of metric and imperial (30 x 1 3/4"). Anyone replaced theirs - if so what size and brand was used and was it a straightforward job.
Also what's the downside (other than the niggle of the vibration) if I leave it to next haul out time.
All opinions, advice, experience welcome.
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Post by sirona on May 17, 2012 17:53:22 GMT
I've replaced my cutless bearing after 2 years on my then new SO45 using a home made extractor so that I could remove cutless bearing without having to remove prop shaft and consequently rudder. It worked reasonably well, but they are very tight and hard to remove. Moreover, 3 years later there is movement in the bearing again...I'm told it's nothing to worry about, so I'm not going to change it yet. My "extractor tool" is at home and my boat is now in the Med. The local mechanics say that a new bearing will quickly wear to the same level (not sure if that is because they realised they would have to drop the rudder to remove prop shaft!) I do not notice any vibration while sailing. I suspect the heavier Autoprop is contributing to the wear. Not sure what is the downside of leaving it until it wears out more. Maybe others can offer insights - I'm no expert!
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Post by ianqv on May 17, 2012 19:59:48 GMT
Hi Robin, You are correct - your shaft will be metric, and anr your P bracket is imperial!! Great huh!! What type of cutlass bearing do you have? is it the "cost reduced" (aka cheap!!) rubber type, or do you have one with a brass outer casing? Check out my thread for cutlass bearing replaement. I used a composite bearing...... ZERO vibration now (which really helps my OCD)  jeanneau.proboards.com/index.cgi?board=general&action=display&thread=2017Best Regards Ian |
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Post by robinwr on May 18, 2012 7:36:29 GMT
Thanks for the comments.
Ours is the rubber inner and resin outer casing - my homemade tool version 1.1 (modified puller made to remove a VW Golf steering wheel) needs modified again and wasn't able to move the bearing.
After a few other heads of knowledge having a look at the amount of play I've decided to get her back in the water tonight and with a newly cleaned and antifouled bottom see if the bearing really does create vibration or if it was just my imagination.
Will put the task on my todo list for next winter and might also tackle the stern gland.
If I get a chance this eveing I will take a few photos and post next week.
Robin
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Post by robinwr on May 22, 2012 7:53:07 GMT
Hi - We launched on Saturday morning but didn't get the chance to photograph the P bracket or the cutless bearing.
Reading Nigel Calder's Boatowner's mech and elect book last night his recommendation is to change when there is 2mm of play per cm of shaft diameter which means 6mm of play. This seems a lot but puts my mind at ease - there was probably less than a mm of play in mine.
Anyway will see how the season goes.
Thanks for the help.
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Post by ianqv on May 22, 2012 11:34:44 GMT
Hiya, I hope the launch all went well!! If you only have 1mm of play - that will be fine. 6mm of play!!!  I dread to think what sort of noise and vibration you'd be getting if it was that bad!! Regards Ian Hi - We launched on Saturday morning but didn't get the chance to photograph the P bracket or the cutless bearing. Reading Nigel Calder's Boatowner's mech and elect book last night his recommendation is to change when there is 2mm of play per cm of shaft diameter which means 6mm of play. This seems a lot but puts my mind at ease - there was probably less than a mm of play in mine. Anyway will see how the season goes. Thanks for the help. |
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Post by h4marine on Jun 18, 2012 9:23:24 GMT
Hi - We launched on Saturday morning but didn't get the chance to photograph the P bracket or the cutless bearing. Reading Nigel Calder's Boatowner's mech and elect book last night his recommendation is to change when there is 2mm of play per cm of shaft diameter which means 6mm of play. This seems a lot but puts my mind at ease - there was probably less than a mm of play in mine. Anyway will see how the season goes. Thanks for the help. As a bearing supplier each manufacturer will have their rated clearances when new and when they need replacing. Ours (Maritex) for a 60.00mm shaft in a 90.00mm carrier. New clearance = 0.28-0.38mm This is made of moisture swell, unscheduled thermal expansion and min running clearance. Replace when it approaches 1.50mm that's 0.25mm per cm of shaft diameter. I'd love to know which manufacturers would be happy with even 1.00mm per cm of shaft diameter. The less movement the better. With rubber you have the added movement that the rubber allows as it deforms under pressure so you will have more than the measured clearance/movement. A few mm at the P bracket can equate to a quite a lot of movement at the coupling. 2.00mm on a 60x240 bearing is over 8.00mm per m of shaft length. |
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Post by ianqv on Jun 28, 2012 18:36:53 GMT
Dear All, H4 is where I got my bearing from. Great to deal with and gave me lots of fab advice. Regards Ian Hi - We launched on Saturday morning but didn't get the chance to photograph the P bracket or the cutless bearing. Reading Nigel Calder's Boatowner's mech and elect book last night his recommendation is to change when there is 2mm of play per cm of shaft diameter which means 6mm of play. This seems a lot but puts my mind at ease - there was probably less than a mm of play in mine. Anyway will see how the season goes. Thanks for the help. As a bearing supplier each manufacturer will have their rated clearances when new and when they need replacing. Ours (Maritex) for a 60.00mm shaft in a 90.00mm carrier. New clearance = 0.28-0.38mm This is made of moisture swell, unscheduled thermal expansion and min running clearance. Replace when it approaches 1.50mm that's 0.25mm per cm of shaft diameter. I'd love to know which manufacturers would be happy with even 1.00mm per cm of shaft diameter. The less movement the better. With rubber you have the added movement that the rubber allows as it deforms under pressure so you will have more than the measured clearance/movement. A few mm at the P bracket can equate to a quite a lot of movement at the coupling. 2.00mm on a 60x240 bearing is over 8.00mm per m of shaft length. |
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I dread to think what sort of noise and vibration you'd be getting if it was that bad!!