Replacing Rudder Bearings

Hello Bav34
The spacer/sleeve on my 39 fits between the rudder and the lower bearing, (not the housing) so tightening the top nut will put axial load on both the bearings and since they are spherical in their housings will "tighten" the steering.

The top nut I have has the clamping screw you describe plus two grub screws that further ensure this nut will not undo. This mod was suggested to me by my Bavaria dealer who apparently had experience of these nuts coming loose.

Before my rudder became tight I was able to lift the rudder up by slinging it with ropes through the aft mooring fairleads to the sheet winches. I suggest lifting the rudder with ropes then taking up the slack with the top nut. With the rudder up the nut can be adjusted by hand. You will have to get wet to sling the rudder but it is possible. When I took the rudder out last week I slung the rudder this way plus three lines around the rudder shaft at the top of the rudder. The boat was up in the slings and we had the rudder hanging underneath but clear of the hull so we could work on the bearings. With this experience I reckon we could do a bearing replacement while in the water albeit flat calm conditions. (but have a travel lift nearby too)

Andrew
 
Ray/Andrew. Here are pics as promised.

Prior to rotating

bearing.jpg



After rotating ... don't worry that it looks as though the leading edge is now in deeper ... it's just the angle that I took the photos

bearingrotated.jpg


The spacer that you mention is obvious. I guess that the bearing is the white disc above it ???

There is a small amount of rudder shaft play evident if you grab hold of the bottom of the rudder and give it a good shake. As I have said it seems comparable to other boats in the yard. When you shake the rudder the bearing can be rotated on the rudder shaft (obviously) but also within the tube that it sits in. It doesn't actually seem loose as such .... it only just turns, but I don't think it should.

What actually holds it in place? I presume that the rudder shaft gets wider at the bottom so that when you slide a new bearing on it can only go so far and that the bearing and tube are tapered so that as the ring at the top of the shaft is tightened, the bearing face mates up to the tube face. Does that make sense?

Just to re-iteratate:

There is no problem with my steering when the boat is in the water. It's certainly not stiff and there's no noise suggesting it's slack either. It's possible that any bouyancy in the rudder is pushing the shaft up into the tube making a good seat for the bearing, hence no obvious problem ... in the water!!

Would be happy to have have your thoughts /forums/images/graemlins/ooo.gif
 
The white disk you show in the photos is not the bearing. It is a spacer to give the rudder something to bear on rather than the bearing holder. After re-reading your description and looking more closely at the photos I see there is a plastic/delrin collar between the disk and the top of the rudder. It is this which determines how far up the rudder can be drawn by the adjustment ring.

There is more of the rudder shaft (collar) exposed between the bottom of the bearing holder and the top of the rudder than on my boat. The bearing holder is bedded deeper in to the hull moulding than mine too. Mine does not have the spacing collar but does have the spacer disk. Maybe the bearing holder is different on the 34 compared to the 37 and 44.

Usually the spacer disk runs free and is more often seen dropped down on to the top of the rudder, I haven't seen one which fits so neatly into the recess for the bearing holder, but that isn't really a problem. It has the advantage of keeping growth and molluscs out. Have a look at the photo which Andrew links us to to see the underside of the bearing holder and the bearing. The bearing itself is like a doughnut. My 44 is the same system as the 37 in the photo. I would think yours is too but we just can't see it.

From your description of the play in the rudder it sounds minimal. I would be reluctant to change anything but just keep an eye on the top ring to ensure it stays clamped and does not unscrew over time. Do you see thread above the top of the ring?

The rudder shaft does not taper. As mentioned above, it looks like you have a collar between the top of the rudder and the spacer disk. It is this which stops the rudder being drawn higher.

I hope I have interpreted the photos correctly. Andrew, any comments?
 
Hi Andrew
Yes my B44 was in the med for 5 yrs and was hauled out for 3 of those winters but I didn't notice any real stiffness at the time we shipped her back 2 yrs ago. However, the steering is so free and smooth now I suspect it was gradually tightening but we didn't realise it.

The cause is curious. The problem is not uncommon but neither have we had a rash of comments on the forum to say it is the norm. There are thousands of this type of rudder bearing (Bav and others) in the Med so if the salinity and water temp were key then we would surely have more complaints. My bearing holder had much less corrosion than the one in the picture you linked to. Even with that corrosion I don't think it is at risk of breaking or the bearing breaking out. There is still plenty of "meat" in the holder yet.

When trawling the web on this I found a couple of other references to corrosion (non Bav) and in one US case the whole bearing mount had to be sawn out and a new one put in with lots of GRP work. So clearly there is potential for this on any of the boats but I am still not sure where to point to the cause.

I have not heard of adding an anode but it could be an interesting experiment. But where to put it? Maybe on the very aft outside of the bearing support case. Perhaps it could take a small hole tapped in horizontally. But against that theory, my folding prop anodes were far less eroded over the past 12mths here in Sydney than in the Med. I can confirm the bearing housing and the rudder shaft and mechanics are electrically isolated from the engine/electrics on my boat too.

Maybe we will hear of more cases and causes to help us understand the problem.
 
Hi Guys,
Yes Ray, I fully concur with your assessment of the photos. Sounds like my 39 is the same arrangement as your 44 and looks the same as the 37 in the link I gave.
I too would say that Bav34 should just monitor the situation. There doesn't appear to be any problems other than possibly wear.

Andrew
 
I've been lurking /forums/images/graemlins/ooo.gif

Thanks to both of you.

As it seems that the white disc is only a spacer, not the bearing, I agree that it's not a problem if it rotates.

I am 'happy' with the amount of play in the rudder and feel well capable of fixing it should it ever become a problem now I have read your posts.

Thanks again. /forums/images/graemlins/smile.gif
 
Hey..

I have the same problem with stiffness on my Bav 39 2007.
I am located in Malta Med.. warm sea temp may have a bearing on the bearing /forums/images/graemlins/smile.gif.. will haul out in winter and check for the corrosion issue....
I do not use the boat often and that seems to be the problem.. that i am not wearing the bearings as much as they are growing...
I lubricated the bearings and got some of the stiffness off but it creeps up after period of non use... its liveable but will have a better look when hauled out...

thanks for the info

Bav 39
 
Here is a hint I heard of for (not) dropping the rudder.

Instead of propping it up from the bottom, you could catch it from the top.

Buy a Hippo bag (£7.99 which will hold a tonne) put the bag under the rudder, tie ropes to the corners and tie those to your winches or cleats and remove the slack.

The plan is to keep the bag high enough so the stock will remain in the tube, and the rudder won't fall out

Once you've knocked your rudder out, tie the bag to the rudder and lower it down gently. You might have to dig a hole under the rudder to get it out fully depending on the draft.
 
Replacing the bushing?

Dear Bavaria rudder specialists
I have a Bavaria 37 2007 and read your communication before (April 2009)taking out rudder and sandpapering the inner part (alternative to drilling according to dealer) of the bushing to get rith of the pressure on the rudder post.

It helped 80%, but apparently I did not take off enough and problem is slowly coming back. Now I realize that Bavaria is using (and sells) a new kind of donut bushing with vertical rollers that allows tightening the top ring without creating the friction problems, They sell it for around 150 Euro which is worth it.

I plan to do either the "in the water trick" and sandpaper a bit more and maybe soon haul out and replace with the new donut. In any case I would like to aks:

1) What makes the rudder slack decrease when tightening the top disk? Is it for sure the rudder post that is tapered in the section by the bushing/bearing or does the bushing have a conic shape also? This matters when I sand paper.

2) When you cut the fixed bushing out (due to corrosions etc.). How did you do that?

Claus
 
Replacing the Bearing

The shaft is NOT tapered where the bearings are fitted so any sandpapering should take an equal amount for the whole area.

I originally thought that tightening the top nut reduced the movement of the rudder and also thought there had to be some kind of taper in the shaft or the bearing housing to allow such an adjustment. When I removed the rudder and replaced the bearing it was clear that the top ring adjustment is only to ensure the vertical location of the rudder is correct and is not too tight to create friction with the spacer plate and the hull. The housing for the bearing was very accurate and it is not tapered as far as I could see. Even if it were tapered the top of the rudder does not push against the bearing so it could not push the bearing into a taper. The top of the rudder has a spacer plate/disk between it and the aluminium bearing housing so tightening the nut/ring at the top of the shaft only pulls the rudder up against the spacer ring and housing.

The shipwright used a reciprocating power saw (Bosch) to cut the bearing from the bottom. He had to be careful not to damage the aluminium housing but the bearing is quite soft and actually melted where it was cut. He took a few narrow slices out so that it could be moved within the housing and then dropped through the slot.

Your report of the needle bearings from Bavaria is very interesting. I think they previously used them in their 'Match' series boats and I saw that type on the web for racing yachts. Do you know if they plan to make the needle bearing types as replacements for all their previous models?

When I wrote about my experience I mentioned that I would use Visconite as bearings. They have been in a year now but the boat has had very little use this past 11mths due to my travel away for family and business. However, after sitting in the water doing nothing for most of that time I am pleased to report that the steering is still 'as smooth as silk'. Too early for real conclusions but so far so good for Visconite.
 
Rudder Lower Bearing..

Hey all....

I hauled out and with yacht on the crane I pulled out the rudder. It was not hard stuck but it did not fall out... I just turned the rudder to port and starboard from below and it came out with its own weight... quite heavy..

I found 2 spacer rings between the lower bearing and the rudder.. (used to clear the hull)

So on first inspection the lower bearing is seized in the alu housing..

Checked the internal diameter and found that it is oval...

Since the alignment is correct I decided to clean the inner diameter of the bearing for now.
I made a dummy shaft same diameter as rudder stock at lower bearing 63mm as a guide, and cleaned out the stuck bearing by a flap wheel abrasive fitted to an electric hand driller.
I gave the bearing some clearence which will be enough until next haul out when i will remove and install a vesconite version... (which i need to get outer measurements and machine localy).

will keep you all posted...

btw in the yacht yard there was an Elan 37 with the same problem.. from what i have seen they have the same bearing provider/manufacturer. Anyone has any idea who makes these.. could it be a Lewmar product?

Bav39
 
Sounds like a good result. I am sure you will be surprised at how little resistance there is now and how you became used to the stiffness as it built up before.

I think there are many european production boats with the same type of bearing material. I guess it depends upon original shaft/bearing clearance, usage and the amount of 'crud' collected over time as to when the bearings will give trouble.
 
Gypsy said:
A few weeks back I asked for advice about changing the rudder bearings for a Bavaria 44 (2002). I received a few good hints and warnings as one has come to expect with the range of experience on this forum.

Yesterday I hauled out and assisted my local shipwright to do the job.

The process is simple but the very fact that the bearing was binding on the rudder shaft made the execution a little difficult. For those who may face the job here is a summary:

1) Undo quadrant clamp and set it back from the shaft.
2) Remove the key between the quadrant and the shaft
3) Loosen clamps of the rubber gator on the stern tube.
4) Place something under the rudder to support is as it exits the bearings/stern tube. It will be heavy!! 60-80kg or more.
5) Undo the top of shaft retaining/locking ring
6) Place a piece of hardwood on top of shaft and knock down with a heavy hammer. We ended up using a 7-10kg sledge hammer. Use a hardwood rod when the shaft goes below the top of the bearing.
7) If the bearing is tight, it will take time and energy to persuade the shaft down through the lower bearing.
8) On the B44 the shaft diameter at the lower bearing is 68mm but tapers after about 200mm inside the gator to 65mm where the quadrant attaches. The top bearing is 50mm.
9) Once it comes free, after 200mm, the rudder will drop like a stone. Be ready, it is heavy!
10) The lower bearing was stuck in the mount. We had to cut it out. The top bearing came out by rotating 90deg and dropping thru the slot.
11) When replacing the rudder, use 3 gorillas to lift it into place with someone in the lazarette to guide it. Quickly put the top lock ring in place.
12) When positioned vertically, tighten the ring to minimize movement. There shouldn’t be much with new bearings.
13) Re-attach the quadrant and check cable tensions.

The steering is now “as smooth as silk”. It is amazing to realise how this must have been gradually binding and adding resistance. There must be thousands of boats (not just Bavs) with this problem creeping up as I write.

I was impressed to realise that the rudder shaft is solid stainless steel!

On a final note, I decided to use a different material for the new bearings. I am not sure what material the Bavaria originals are made of. They are white, they could be Nylon or Delrin or something else. I searched the web for alternative materials as I don’t want to do this every 5-6yrs. I found a material/product called Vesconite which claims to have 0.07% size change in 100% humidity (compared to 3% for nylon). It is used in mining pump and marine bearing applications. I bought tube of appropriate raw dimensions and found a machinist to create what I needed modelled on Bavaria originals which I purchased.

I am really impressed with the smoothness and lightness of the helm. Was it this good when the boat was new? I can’t remember. The real proof of the Visconite will be in 5yrs. Watch this space.

Anyone want to buy a pair of Bavaria 44 rudder bearings, unused?
Click to expand...

Footnote: Glad it all works now.

Did you recon the lower housing when the bearing was removed? It was most likely scored by corrosion, and if not treated, will advance failure of the new bearing. .

Top bearings are not subject to corrosion and moisture so need not be replaced -for the benefit of others who might be facing these decisions.

Your item 12 - the rudder requires to be equidistant beteen intermediate bearings, not tightened to its max extent. The positioning grubscrew is important.

If you have machined the new bearing to generous tolerances around the stock, the presence of sea water will eventually permit algae to set up in crevices in the bearing. This will advance stiffness in the steering. A water proof lubricant in the lower bearing is strongly advisable.

Your choice of new material for the bearings will be interesting to others. Nothing I have heard of, sadly, eleiminates the design fault that we all (eventually) experience - in my case 3 times!

You went to the trouble of listing all this - my earlier posting covered it all in full detail.

PWG
 
Vesconite is OK but there are a number of alternatives in this area, however if it works for you then it is probably all that you need.

Other materials include Railko,Thordon,Orkot and the one we work with Maritex.

Composites are very interesting, as ingredients can be added that can alter how the surface works. Many compsoites suffer in warmer waters as fricion induces localised heat and expansion which can result in bore closure. Make sure you work to manufacturers tolerances.
 
Bavaria 44 Rudder Bearings

Hi Gypsy,

I have a Bavaria 44 (2002) which I leave in Greece and sail each summer out of the island of Leros.

In the season of 2008, the rudder became increasingly stiff to turn at the helm, so much so that it would hold a steady course when under sail. I asked the Greek boatyard on Leros to remove the rudder and replace the bearings. They did remove the rudder but saw fit to only clean the bearings. When the boat went back into the water in May last year , the result was good, but the stearing became incresingly tight over the next 4 months.

On taking the boat out again last September (2009), I complained and asked them to replace the bearings with NEW ones. I am due to leave for Greece on Sunday, and on checking their progress with them yesterday, they told me that they had once again removed the rudder, and once again did not replace the bearings, but machined them down to allow more freedom of movement. I love the Greeks, but they can be stubborn

I need some guidance. Do you still have your bearings for sale? Or should I have some new ones made from the special material you mentioned, and if so, is this difficult and expensive.

It is very hard for me to communicate with the Greeks, so if I could take the parts with me, maybe I could get them to do it whilst the boat is still out of the water.

I also had another problem in that in 2008 I had the boat anti-fouled whilst in Biograd, Croatia. during this process, they had to replave the anodes, and disaster struck on the one which is behind the prop. I was in the boat when there was a loud banging and rushed down the ladder to find that the mechanic had knocked the prop off with a hammer, instead of using a puller. When the boat was relaunched, I motored away from the dock to hear a loud "screeching" noise coming from under the boat. I returned to the dock, had to pay to have the boat lifted out again, and they checked the sail-drive, oil levels etc and flatly refused to do anything about it. Many mechanics came aboard after she was re-launched, and eventually said all Bvarias suffer from this. I had a schedule to meet and left to sail down to Greece. Volvo did not respond to my queries.

The noise kicked in at 900 rpm and disappeared at 1400 rpm. Does not occur in reverse.

I asked the Greeks to fix it last year, they had a go at machining a bearing, which only resulted in the noise occurring between 900 rpm and a new upper limit of 1700 rpm. Yesterday they told me telephonically that they had opened up the sail-drive and found that an internal anode had moved and was causing the noise ( no sea trial undertaken) and that all else was good inside the sail drive. I don't believe them as I can't find an internal anode on any sail-drive diagram. Does anyone know of this problem?

Hope to hear back.
 
Bavaria rudder problems.

Interesting reading we purchased a Bavaria 37 in 2006 and had to replace the lower bearings on 2008 as they seized completely. Now two years later in 2010 we believe we are in the same situation. The steering is nearly as tight as before and we are lifting the boat on Monday to hear the bad news.

Is it Bavaria parts, is it the commissioning or is it something else. Do you have to use bavaria replacement parts or can you get something that is in more regular use.

Would like to know of other experiences expecially in the UK.
 
Rudder bearing problem

I m living in Japan and have B38 2002.
Last month we got same situation.
Before tow yeas ago, I felt rudder will be little loose or shaking.
Last year, rudder was little tight to move so autopilot was broken by overload.
This year, 2month ago there was no need Autopilot for go streight.
Last month, very thight and not stear propaly.

Oviously the problem caused by Aluminum housing corrson.

I guess some rasons.

Rudder had a gap in bottom and get more sea water in housing.

I applyed bottom paint for the bottom part of housing. Bottom paint include cooper so electical corrosion will occer.

I changed my habour 2 years ago. Sometime the shore power supply got grounding trouble.

Also inside engin slot wire(cooper tubu)comes in contact the Aluminum housing. This helps also electric corrosion faster.

Below measage form Bavaria
"If the aluminum corrodes it means something is wrong with the electrical connection around your boat or you park close to a big steel construction."

Anyway only I can do is clean up inside and replace bearing not housing.
Repalce the housing cost too much and take a long time. Even I do not want summer time.
I can not get Vesconite. Is the Vesconite looks like a cutless bearing?

Please let me know how to order the Vesconite (size etc).

Thanks for your info.
 
Vesconite are a South African company, but have a number of overseas offices. Take your pick from these phone numbers:
USA (7-3EST) 1 866 635 75 96 / (713) 574-7255
UK 0800 731 9745 / 020 3239 9044
UAE 800 027 01 03
Australia 1800 833 448
Canada 1 866 682 3484
Chile (2) 570 3855
Hong Kong 800 930 211
Ireland 1800 552 711
Netherlands 08000 223 805
Portugal 800 827 007
Brasil 0800 891 87 16
New Zealand 0800 450 878
Germany 04 43 18 92 38 99

Or contact them using their email form
 
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