Rudder bearings info please

[chrisgee]

I bought a boat last Autumn and the owner had the rudder bearings replaced. They worked fine for a few months,then the boat was lifted for the Winter. I noticed that by Sept the rudder was getting stiffer and now after this years 8 weeks use it has got really stiff.
I suspect they were not the correct ones and may need doing again during the next lay up.
Is their some way I can lubricate them just for the next 3 months before she is lifted again

I saw a suggestion somewhere about squirting PTFE down the top of the rudder tube would this work?

Thanks for any info available?

 

[dom]

Are these glide or roller bearings, and if the former, do you know what they are made of?

 

[Praxinoscope]

I agree with dom, it’s essential to know the type of bearing and what they are made of. A friend used a similar ‘cure’ on his rudder bearings last season, and squirted lots of WD40 down the tube, unfortunately the material the bearings were made from reacted to the WD40 and swelled making them even tighter. He then spent weeks during the Winter dismantling the rudder system and replacing them.

 

[savageseadog]

Probably made from the wrong material

 

[RichardS]

I agree with dom, it’s essential to know the type of bearing and what they are made of. A friend used a similar ‘cure’ on his rudder bearings last season, and squirted lots of WD40 down the tube, unfortunately the material the bearings were made from reacted to the WD40 and swelled making them even tighter. He then spent weeks during the Winter dismantling the rudder system and replacing them.

Unless the bearings were made from a soft plastic like polystyrene, they would have been even tighter without the WD40.

If they are hard plastic and the tightness is due to corrosion of the bearing cage, the WD40 might make things a little bit easier for a very short time but probably not.

If the bearings are metal against metal, the WD40 will probably make things a lot easier but it will be relatively short lived .... although in all these cases, assuming that the bottom bearing is below the waterline, it will be very difficult to get any meaningful lubrication into the bearing unless the boat can dry out somewhere.

Richard

 

[vyv_cox]

Some people have had rudder bearings made from nylon, which swells about 10% in water. WD40 in air would probably not cause problems but not sure in water. Quite honestly I think a cooking oil would be as effective.
The correct plain bearing material is acetal.
All assuming plain, not roller bearings.

 

[bitbaltic]

It’s not a Hanse is it? Rudder problems common on older ones. Just checking.

 

[Neil_Y]

As has been said the tightness could be a few things, Polyacetal (Delrin) is a soft material and under load can creep and deform, it does also absorb some moisture so it needs a clearance to allow for this when it's made. What can happen is corrosion (which takes up more space than the original metal) can squeeze the bearing to make it tight.

It's probably a Delrin type material you have as this is used commonly on many yachts but...it could also be metal, or a roller bearing. It may be ours but I doubt it if it has tightened up as ours have lubricants in the material and don't creep.

I would use ACF-50 as a first try, as it can help if there is any corrosion in the metal parts and it will penetrate. It's way better than WD as a lubricant and corrosion cure.

Good luck, if you are unsure get some photos, there are people here who will have seen most types of bearing.

 

[chrisgee]

As has been said the tightness could be a few things, Polyacetal (Delrin) is a soft material and under load can creep and deform, it does also absorb some moisture so it needs a clearance to allow for this when it's made. What can happen is corrosion (which takes up more space than the original metal) can squeeze the bearing to make it tight.

It's probably a Delrin type material you have as this is used commonly on many yachts but...it could also be metal, or a roller bearing. It may be ours but I doubt it if it has tightened up as ours have lubricants in the material and don't creep.

I would use ACF-50 as a first try, as it can help if there is any corrosion in the metal parts and it will penetrate. It's way better than WD as a lubricant and corrosion cure.

Good luck, if you are unsure get some photos, there are people here who will have seen most types of bearing.

 

[chrisgee]

Thanks Neil ( and all others) I will try the ACF 50 ( takes me back to my Honda Fireblade days) - I reckon the yard replaced them with Nylon.
Can you get me a new set ,for a 1999 Dufor 39CC which is the same steering set up as the Dufour 38/41 Classic.?

 

[Neil_Y]

Our bearings are all made to order, so we just need to know the details of the vessel, shaft OD, bearing carrier ID, Length, any flanges, what it is lubricated with, material of carrier and shaft.

We then calculate the minimum clearances needed to allow for the variables like temperature change and expansion etc. When you are working to 0.05mm it's best you get the right size otherwise our machining to + or - 0.05 is a waste of time.