Rudder Bearing Replacement

J

johnsilver2

Active Member
Joined
25 Aug 2009
Messages
45
Location
Me Cheshire, boat Holyhead SC
Visit site
My rudder bearings on my Rival 31 have a bit of play in them especially at the top. I have removed the rudder so that I can now see what I am faced with. The bearings are plain tufnol in a glassed in fibreglass tube. There is a section of bearing at the top and a seperate section at the bottom.
Has anyone got any experience of removing and replacement the bearings of this type?
There is only a few inches of clearance above the upper bearing so they can not be drifted out from above.
There is a machine screw in the glassfibre tube which I had assumed held the bearing in place but doesn't, it just acts as a stop for the lower bearing.

I am wondering if it is best the leave them in place and perhaps 'line' them with epoxy. I have a length of old prop shaft which is the same diameter as the rudder stock. I could wax this and insert after coating the bearing surfaces with epoxy. Any one got a view on the likely success of this?
I have heard of this type of thing being done with the bronze foot bearing at the bottom of the skeg using epoxy and a 'sintered' filler although I don't know what sintered filler is. Is this available from West Systems?

TIA................Andrew
 
I have a very similar sounding arrangement. I managed to remove the tufnol bearings by knocking them out from below (top bearing) and above (bottom bearing), using a length of round steel bar. Tap around the bearing to ease it out. With your access problem you might be able to do a similar thing with a turned stepped bar, inserting it through the bearing and using the shoulder to do the tapping.
If this is to no avail then a puller will be needed. A flat piece of steel drilled and threaded in the centre to take a length of studding (or long bolt), pulling through the centre of a short length of scaffold tube is a popular choice. Your flat piece of steel will be craftily designed to pass through the bearing when tilted yet sit securely on top of it. Screwing yoiur stud carefully into it allows the bearing to be drawn in a most satisfactory manner. If the sizes are chosen carefully this puts no stress on the bearing tube. My replacement bearings are bronze and that is probably the only way they could be removed without damage.
I would not be keen on the epoxy repair myself, seems a lot of fuss and I would find it difficult to have confidence in it.
 
Rival Owners Association Web Site - Good Source of Technical Information

Try searching on the Rival Owners Association Web Site and asking the question there. I am sure you will get the advice you need from this source.
 
Bearing material is designed to have mechanical strength so that it does not deform under pressure and is dimensionaly stable when subject to moisture and temperature changes, the materials are also developed to be non abrasive to the shaft.

The dimensional changes are accurately known and the operating clearance is derived from these figures. I believe you may face a risk of seizing the rudder should you sail it to warmer waters if the rudder is working hard or you could end up with play in the system and rapid wear back to the size it is now, you may also wear the rudder shaft.

Old bearing removal can be difficult and involve some brute force and cutting up of the old bearings but you will then have a system you can rely on for a number of years. As others have suggested talk to other owners of the same design.

This is a table to calculate the bearing clearance for new rudder bearings.
http://www.h4marine.com/Downloads/Maritex AQUARIUS General Calculator REV 20100519.xls
You can see underneath the table the allowances for clearances are given, if you use epoxy mix to sleeve a worn bearing the mechanical properties of the combined old and new materials bonded together will not be known and hence the clearances you use may or may not be suitable.

It can be a difficult job but hopefully you don't have to repeat it for a number of years.
 
You must log in or register to reply here.

Share this page

Top