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Post by ianqv on Feb 14, 2012 12:41:33 GMT
Hi All,
Any suggestions are welcome....
I have an S/O 37 (2002) 4OHP Volvo penta, 3 bladed feathering prop.
Last year when I was lifted out my cutlass bearing had play in it. So I replaced it with the Jeanneau "all rubber" type bearings.
I got lifted out yesterday - and I've got exactly the same play (up and down movement) in my cutlass bearing.
When I replaced my last bearing I did checked for alignment and it was found to be spot on!!
Could it be that the 3 bladed feather prop weighs more than the standard prop?
Any suggestions are welcome as to why I have worn another cutlass bearing so quickly.
Many thanks in advance
Ian
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Post by davideso37 on Feb 15, 2012 12:47:22 GMT
Ian,
I have the SO37 with the Yanmar and a 3 blade folding prop. After 3 years the rubber bearing had excessive play and the yard claimed that it was a very big prop for the size of the bearing. At the next haul out we replaced the rubber with a maritec bearing that was turned up to the required size. It has performed very well since but the job was expensive. For the cost of the bearing you could have replaced the standard Jeanneau rubber bearing every year and been ahead but the labour in removing and reinstating a feathering prop every year might also be expensive.
Regards
David
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Post by j on Feb 15, 2012 13:53:30 GMT
Is it possible that your prop is not balanced?
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Post by ianqv on Feb 15, 2012 19:44:32 GMT
Ian, I have the SO37 with the Yanmar and a 3 blade folding prop. After 3 years the rubber bearing had excessive play and the yard claimed that it was a very big prop for the size of the bearing. At the next haul out we replaced the rubber with a maritec bearing that was turned up to the required size. It has performed very well since but the job was expensive. For the cost of the bearing you could have replaced the standard Jeanneau rubber bearing every year and been ahead but the labour in removing and reinstating a feathering prop every year might also be expensive. Regards David Hi David / all Thanks for your advice. I think I've found the problem.... you know what they say - check the basics first!! Well.... I removed my prop today, and then removed my cutlass bearing. NOTE my prop shaft is still in place at this point. It is clear that the prop is NOT aligned as the prop wants to spring down resting on the bottom of the p bracket. So what I plan to do is adjust the engine mounts so the the shaft is no longer sprung and sits nicely / central in the p bracket. I'll take some pics so you can see what I mean. DAVID - Can you explain what you mean by "reinstating a feathering prop" - I removed mine in one lump from the center bolt. I was just going to put it back on the same way. I just want to make sure I'm not missing something??  Cheers Ian |
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Post by sitara on Feb 15, 2012 20:38:32 GMT
When I replaced the cutlass bearing on my SO 29.2 I found a significant buildup of calcium (?) deposits on the shaft within the bearing area. This no doubt contributed to the rapid wear that I experienced. Since replacing the bearing and cleaning the shaft I have had no problems with excessive wear for a couple of years at least.
Not sure about adjusting engine mounts so the shaft is central in the P-bracket. Engine alignment with the shaft should ideally be done in the water so that there is no hull deformation from the boat sitting on the keel.
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Post by ianqv on Feb 15, 2012 22:51:20 GMT
When I replaced the cutlass bearing on my SO 29.2 I found a significant buildup of calcium (?) deposits on the shaft within the bearing area. This no doubt contributed to the rapid wear that I experienced. Since replacing the bearing and cleaning the shaft I have had no problems with excessive wear for a couple of years at least. Not sure about adjusting engine mounts so the shaft is central in the P-bracket. Engine alignment with the shaft should ideally be done in the water so that there is no hull deformation from the boat sitting on the keel. Hi Sitara, Good point - thank you. As there is a prob, and is more than likely out of alignment, looking at the cutlass bearing it is worn on the bottom. I will adjust it - but will take your advice and will re-check once afloat to see if there is any change. Many thanks Regards Ian |
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Post by davideso37 on Feb 17, 2012 9:02:19 GMT
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Post by ianqv on Feb 17, 2012 19:00:02 GMT
Many thanks WOW I see what you mean! I've got one of the bruntons feather prop. |
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Post by electricmonk on Feb 23, 2012 13:32:48 GMT
Hi David / all Thanks for your advice. I think I've found the problem.... you know what they say - check the basics first!! Well.... I removed my prop today, and then removed my cutlass bearing. NOTE my prop shaft is still in place at this point. It is clear that the prop is NOT aligned as the prop wants to spring down resting on the bottom of the p bracket. So what I plan to do is adjust the engine mounts so the the shaft is no longer sprung and sits nicely / central in the p bracket. I'll take some pics so you can see what I mean. DAVID - Can you explain what you mean by "reinstating a feathering prop" - I removed mine in one lump from the center bolt. I was just going to put it back on the same way. I just want to make sure I'm not missing something?? Cheers Ian[/quote] Don't waste your time aligning the shaft with the boat out of the water, what you have observed is what would be expected with the boat ashore. Check the alignment when the boat is launched and the rigging is tuned. Then make adjustments if required. IF the shaft alignment is correct then calcium deposits on the shaft and silt in the water are the culprits that are wearing out your cutlass bearings. A harder cutlass bearing material will resist wear , but will accelerate wear on the shaft, its a no win I am afraid. Fitting a RD coupling makes checking alignment easy. |
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Post by h4marine on Feb 27, 2012 13:14:06 GMT
Ian[/quote]
A harder cutlass bearing material will resist wear , but will accelerate wear on the shaft, its a no win I am afraid.
[/quote]
I have to disagree as we supply hard (not elastomeric or nitrile rubber) shaft bearings to everything from small yachts to superyachts and submarines.
The latest bearing materials for water lubricated shafts suffer less bearing wear and have seen no reported shaft wear. The reasons as you say are marine growth and silt, but what we believe is that soft materials deform to allow abrasives to imbed, they also give under water fild pressure as the shaft tries to flex under thrust loads, the water film collapses and the bearing effectively runs dry until the water fil is established.
Wth a hard bearing as the shaft tries to flex it may collapse the water film and it will run dry but there has been less movement as the tolerance hasn't changed, the latest materials have inbuilt lubricants and also chemistry to resist marine growth the water film is established and the shaft is straight again.
You may also find despite the shaft end being aligned with the engine coupling that the bearing isn't aligned with the shaft. If you have a dry run with a new bearing installation you can check bearing carrier alignment, as the bearing can be slid up a shaft and can be rotated by hand in the carrier. The shaft needs to be chocked of course.
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Post by ianqv on Feb 27, 2012 23:00:54 GMT
Hi All, I have now fitted the H4 fully composite bearing. I found the guys at H4 so so so helpful and had all the time in the world to get me the right product. The product arrived VERY quickly, and I fitted it at the weekend. Sadly my old Jeanneau bearing did not stand the test of time - but not wishing to put the Jeanneau product down... my shaft WAS out of alignment. BUT... I had as much play between the shaft and the bearing, as I did between the bearing and the P bracket!! With the H4 bearing I was able to turn it down to fit precisely, and then set in on a bed of epoxy. I also crossed drilled the bearing so it was held each side by a grub screw - but I only fitted the grub screws once the epoxy had cured. Here are the pics........... This pic just shows the cutlass bearing in the P bracket - ensuring i had turned it down enough Many thanks to H4 Regards Ian  |
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Post by ianqv on Feb 27, 2012 23:03:03 GMT
This pic shows that I have achieved perfect prop alignment in the P bracket - please note, I will recheck when launched.  |
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Post by ianqv on Feb 27, 2012 23:07:35 GMT
Sorry for the out of focus.... this just shows the bearing cross drilled. I meant to say... I aligned the prop shaft using a combination of two methods.... 1/ Got good old Dad to look at he shaft in the p bracket as I adjusted the mounts 2/ with the cutlass bearing fitted in a dummy run - checked and adjusted the alignment at the gear box connection I found using a combination of the two methods worked really well.  |
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Post by ianqv on Feb 27, 2012 23:08:38 GMT
Bearing installed...........  |
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Post by ianqv on Feb 27, 2012 23:10:22 GMT
Just from another angle......  |
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Post by electricmonk on Mar 7, 2012 12:36:20 GMT
Ian,
Yes its all very nice BUT your engine WILL be out of alignment when the boat is out of the water, and its a long way out of alignment to, now you have aligned it on the hard, it WILL be out of alignment when the boat is launched - by a lot.
The only way to check alignment is with the boat afloat and the rig tuned using feeler gauges at the propshaft flange or feeler gauges and a R&D type coupling.
sorry!
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Post by ianqv on Mar 7, 2012 12:58:56 GMT
Thanks for that....  In my last post i did mention that I would be re checking when re-launched. How I viewed it.... it was WAY out of alignment anyway, so aligning it did not do any harm. My rig has just been re-tensioned (for another job). However, re-checking this in the water is not as easy as it sounds. Because I have a rope cutter, if I move my prop shaft back any further than about 15mm - I'm stuffed!! as the peg will drop out of the "V" location on the P bracket. I plan to clamp the shaft about 10mm away from the stern gland. I will of course up date the thread once re-launch (end March). Best Regards Ian |
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Post by ianqv on Mar 7, 2012 19:17:17 GMT
Ian, Yes its all very nice BUT your engine WILL be out of alignment when the boat is out of the water, and its a long way out of alignment to, now you have aligned it on the hard, it WILL be out of alignment when the boat is launched - by a lot. The only way to check alignment is with the boat afloat and the rig tuned using feeler gauges at the propshaft flange or feeler gauges and a R&D type coupling. sorry! Hi Electricmonk.... or anyone else who may know, First of all I'm not asking this to be a smart arse - I just wish to understand as I'm a bit confused!!. This is my understanding - when new boats are commissioned / launched the manufacturer advises that the prop shaft alignment is checked, and if required adjusted. However, I was told by a Jeanneau dealer that Jeanneau do not advise this So two questions really... is it correct that "other yacht" manufacturers advise for this check to be done? And can anyone else confirm that Jeanneau do NOT advise this to be done? if this is the case... why not? (sorry thats 3 questions!!!). Confused.com Ian |
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Post by electricmonk on Mar 7, 2012 22:35:48 GMT
Ian,
ALL GRP boats are like jelly, except they never "set" they have a different shape in the water and out.
Two things,
BEFORE you launch the boat mark the propshaft inside by the stern gland so you can re align the prop cutter without diving underneath. Do it out of the water so you can practisel and ensure you get it right. Paint or pentel pen works for me.
As for propshaft alignment it should be checked every season along with the rest of the engine maintenance if the Jeanneau agent said different lets give him/her the benefit of the doubt and suggest they misunderstood - or they thought you had a saildrive.
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Post by Peter123 on Mar 12, 2012 18:17:19 GMT
I had to replace the cutlass bearing on my 36i after only 2 seasons and now after only one more it feels a little loose again. I think the shaft is aligned OK.
Question: How much play between the shaft and the bearing is acceptable before the bearing should be replaced?
I'd be very grateful for any comments and advice. Thanks.
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Post by j on Mar 14, 2012 4:19:11 GMT
Question: How much play between the shaft and the bearing is acceptable before the bearing should be replaced? From Nigel Calder's "Boat Owners Mechanical & Electrical Manual" At the annual haulout, flex the propeller shaft at the propeller; if there is more than minimal movement (1/16 inch of clearance between the shaft and bearing per inch of shaft diameter), the bearing needs replacing. Also... www.diybob.com/diyCutlessBearing.htm |
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Post by Peter123 on Mar 15, 2012 19:00:13 GMT
J,
thank you. ..
So Nigel Calder says 1/16 inch, diybob (in the link) says "Replacement is due when the prop shaft starts to shimmy or when the shaft shows movement of about 3/16 of an inch".
That's 1.5 mm or 5 mm .. I've heard people say 0.4 mm ..
Mine moves just slightly when I swing on it ..
To replace or not to replace .. that is the question.
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Post by ianqv on Mar 15, 2012 21:19:06 GMT
5mm!!!!!!!!!!!!!!!!  That is a LOT of play to have! |
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Post by tedp on Mar 15, 2012 21:35:17 GMT
I had my cutlass bearing replaced the previous winter, and this time there is the same amount of play in it again, about 1-2mm. I also had the prop balanced last year and during the last season it was noticeably less noisy than it was the season before. Also, I found that running the diesel at about 3000 revs for about 10 minutes once in a while tends to reduce the noise at lower revs which I normally use when cruising. It seems to smooth out the engine and the prop shaft. So I plan to do a check every year and see what difference I find. If it doesn't increase beyond what it is now, and if the noise doesn't return, I plan to leave it as it is.
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Post by ianqv on Mar 27, 2012 20:38:23 GMT
Hi All,
Relaunched last week. So I thought I had better re-check the coupling alignment.
Yes it had moved now it is afloat.
After a few hours of mucking around I have finally got it down to a tollerence which I hope is ok?
I got it within a 3 thousandths of an inch (0.003 on the feeler blade). I tried to get it to zero - but got the feeling this was not ever going to happen.
Would anyone know if this is close enough??
Many thanks
Ian
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