Cutlass bearing worn out again!

[Ianqv]

Hi All,

Any suggestions are welcome....
I have a Jeanneau 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

 

[sailorman]

Hi All,

Any suggestions are welcome....
I have a Jeanneau 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

it doesn help you but since i re-engined + shaft & cutlass 11 yrs ago & 900 hrs running its still the same bearing used in the silt laden North Sea East Coast

 

[Ianqv]

Cutlass bearing

Thats made me feel much better.....

Ian

 

[BlueSkyNick]

Are you checking alignment with the boat afloat or ashore?

Has to be afloat to be sure, in case of any distortion in the hull compared to ashore.

 

[ithet]

I have this same problem. Replaced three years ago, then following year - left it be last year although loose - but now pretty wobbly. PO had replaced year before I bought. Alignment checked and redone, but still problem. Also wear is even and central on the bearing. Wonder if the shaft is a little worn and so allows grit to get in accelerating wear? Thought I might try 25mm instead of 1 inch? Do some makes of bearing go looser than others perhaps? Always seems OK on fitting.

 

[Ianqv]

cutlass

Hi

Many thanks for the suggestion...
I checked the alignment whilst ashore!! I will be sure to check it again whilst back in the water.

Many thanks

Regards

Ian

p.s if anyone has any other ideas whilst I'm still ashore - please please do let me know - cheers!

 

[Ex-SolentBoy]

How much play is there?

 

[Ianqv]

cutlass bearing

I reckon a couple of mm up and down movement only

Cheers

Ian

 

[Neil_Y]

Is the bearing carrier aligned? you could always try a composite but then I'm biased.

Use a clearance fit bearing chock shaft and see if you can spin bearing in the carrier, you should be able to.

 

[Neil_Y]

Actual bearing clearances new and when ready for replacement can be found on our website.

 

[rotrax]

Hi

Many thanks for the suggestion...
I checked the alignment whilst ashore!! I will be sure to check it again whilst back in the water.

Many thanks

Regards

Ian

p.s if anyone has any other ideas whilst I'm still ashore - please please do let me know - cheers!

How much does the prop overhang the cutlass? I believe a rule of thumb is something like 3x shaft diameter. If you have more than this it can cause vibration and premature wear. Hope this helps.

 

[Ianqv]

Actual bearing clearances new and when ready for replacement can be found on our website.

Email sent.

Regards

Ian

 

[kds]

Did the bearing have time to dry out.
I am just fitting a composite bearing and it is loose. The agent assures me it will take up water and expand.
I hope so.
Ken

 

[little_roundtop]

Could it be the prop?

Could your feathering prop not be unfolding properly? If it doesn't deploy properly it will induce a wobble in the shaft that would certainly wear the bearing.

Perhaps you should check your prop?

 

[Bilgediver]

I reckon a couple of mm up and down movement only

Cheers

Ian

ONLY a couple of MM and I worry anout 0.4MM

Is there any chance your propeller is out of balance?

 

[Talulah]

Did the bearing have time to dry out.
I am just fitting a composite bearing and it is loose. The agent assures me it will take up water and expand.
I hope so.
Ken

Composite bearings are glued in with a low melting point Araldite. They don't expand.

I'm sure Neil Y of H4Marine will be along soon to explain.

 

[haydude]

it doesn help you but since i re-engined + shaft & cutlass 11 yrs ago & 900 hrs running its still the same bearing used in the silt laden North Sea East Coast

An unbalance in the propeller can cause vibrations that eventually will wear the bearing.
Is that your case? Can you feel vibrations, even minimal? You may want to check your propeller balance and alignment with the shaft.

I am coming from a recent experience of three Volvo Penta folding propellers that all came new with significant defects in the hub, so it is not an uncommon problem.

 

[Neil_Y]

Did the bearing have time to dry out.
I am just fitting a composite bearing and it is loose. The agent assures me it will take up water and expand.
I hope so.
Ken

What! sounds very odd to me, we supply composite bearings as below.
Are you sure you are not talking about a thermo plastic? rather than a composite.
Thermo plastics are whole different ball game.

I'll run through a clearance calculation for a Maritex composite. to be fare as I don't want to be seen as just promoting one material. The others available are Thordon, Orkot, Railko, Tenmat, ACM. Maritex is probably the most expensive of these but has consistently found happy customers who've previously had wear rate issues or problems with other materials.
25.00mm shaft 1.5"ID (38.10mm) carrier

New clearance on shaft is 25.12-25.22 change when it gets to 25.60mm (0.5mm movement)

Clearance in the carrier new is 0.2-0.3mm, this is filled with epoxy (araldite 2011 is good as it melts at a low temp)
Moisture swell will be less than 0.03mm bore closure (less on OD)= almost nothing
Thermal swell can be 0.06mm but we're talking 40deg+

Maritex fit bedded on epoxy and it is the adhesive which will show more swell than the bearing as it has no fibre reinforcement and is epoxy not phenolic.

Look very closely at data sheets as some manufacturers claim no moisture swell when they do swell, there is also quite a range of thermal expansion figures and as this will almost always be greater than metal some friction and warm waters can cause problems especialy if the fitting clearances havn't been kept to.

Get your sums right and fit them correctly and they are a huge improvement over rubber.

They look like this after several years wear

 

[sailorman]

An unbalance in the propeller can cause vibrations that eventually will wear the bearing.
Is that your case? Can you feel vibrations, even minimal? You may want to check your propeller balance and alignment with the shaft.

I am coming from a recent experience of three Volvo Penta folding propellers that all came new with significant defects in the hub, so it is not an uncommon problem.

I do not have a problem
you got the wrong poster

 

[Fr J Hackett]

You don't say how and where you checked the shaft alignment. Is it possible you have a bent shaft? If you are going to change the bearing draw the shaft and check it for wear and straightness. What are your engine mounts like if they have gone soft you may well have a good alignment measured statically but the engine moving on soft mounts could induce wear.