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Rudder bearing symptoms?


MaggieA

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My steering has been developing a sound over the last few months, which seems to be coming from the rudder area - hard to locate. When I pull up on the tiller arm - this stops the sound. I do not have any impingement in movement from the rudder; there is no clunking, and moving the tiller arm is smooth in all directions. There is some very slight shudder, but that’s it/ I’m trying to establish what the sound could be, and whether it’s a possible bearing issue.

I’ve checked the prop - no play in this, so that’s been discounted. Any ideas?  I’m concerned that it could be the rudde bearings just starting to go. If so, what are the symptoms, and how easy is it to replace them, with the Boat in the water?

 

Thanks All.

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24 minutes ago, MaggieA said:

My steering has been developing a sound over the last few months, which seems to be coming from the rudder area - hard to locate. When I pull up on the tiller arm - this stops the sound. I do not have any impingement in movement from the rudder; there is no clunking, and moving the tiller arm is smooth in all directions. There is some very slight shudder, but that’s it/ I’m trying to establish what the sound could be, and whether it’s a possible bearing issue.

I’ve checked the prop - no play in this, so that’s been discounted. Any ideas?  I’m concerned that it could be the rudde bearings just starting to go. If so, what are the symptoms, and how easy is it to replace them, with the Boat in the water?

 

Thanks All.

Sounds like a bit of sideways slack ''common'' where the rudder stock sits in its cup on the skeg. But what type of top bearing have you? A ball race type which usually have a grease nipple to grease it, or a simple plain bush type bearing?.

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3 minutes ago, MaggieA said:

Hi Bizzard,

 

I have a ball race type top bearing, with a nipple grease gland.

Try giving it a good  old greasing with a gun.  As well as lubricating it, it is to chase out any water thats got into it from either below or above.  Any damaged or bent propellor blades? as these this can cause vibration or knocking.

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Hi Maggie

A couple of thoughts: how often do you grease up this top bearing?

If the bottom cup bearing needs replacing, it is definitely a job that has to be done in a dry dock, but it should not be complicated or expensive, and it can be assessed whilst still in the water, by a feel round the bottom of the rudder stock and the cup, by an arm down the weed hatch.

 

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I’ve had the Boat three and a half years, & I’ve not greased it during that time (I’ll do the walk of shame) - simply because I didn’t know that this should be on the ‘servicing list’. In fact, it came with the grease nipple well painted-over...

 

what is the best type of grease to use? Would stern gland grease suffice, or does it need to be white lithium?

No damage to the prop that I can see - it seems to spin freely and true on the prop shaft.

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Best is a general purpose grease like Castrol LM but stern tube grease will not cause any problems.  The grease is really only there to stop the bearing going rusty and expiring therefrom. The rate of movement and the loading are pretty small so there is very little need for lubrication as such.

Try to give the bearing one or two grease gun strokes each week the boat is used and whenever you set off after a spell of inactivity. 

Your symptoms sound like slack in the bottom cup.  How much play is there when you pull up and then push down on the end of the tiller?. Is it the same with the tiller straight and with it as far as it will go to left and right?

N

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17 hours ago, BEngo said:

Best is a general purpose grease like Castrol LM but stern tube grease will not cause any problems.  The grease is really only there to stop the bearing going rusty and expiring therefrom. The rate of movement and the loading are pretty small so there is very little need for lubrication as such.

Try to give the bearing one or two grease gun strokes each week the boat is used and whenever you set off after a spell of inactivity. 

Your symptoms sound like slack in the bottom cup.  How much play is there when you pull up and then push down on the end of the tiller?. Is it the same with the tiller straight and with it as far as it will go to left and right?

N

There is no play at all when pushing up/pressing down on the tiller arm, as well as with the tiller arm full left and full right. 

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On that basis I would expect the cup to be OK.

Try greasing the top and double check there is nothing fouling the rudder (go down the weedhatch and feel the front edge as far as you can).  If that doesn't cure it you will have to think about an out of water (or underwater if you know any divers) looking at.

Changing the top bearing should be easy, provided rust has not stuck all the bits together. Remove the rams head, then the bolts that hold the top bearing down, then pull the bearing and housing up and off the rudder stock.  Remove bearing from housing. Replace the bearing with a new one and the refit in reverse order. Hardest parts will be getting the rams head off, undoing the bearing bolts, removing the housing (take the paint off the stock), and getting the bearing out of its housing.:rolleyes:

N

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On 15/01/2018 at 13:30, Stilllearning said:

Hi Maggie

A couple of thoughts: how often do you grease up this top bearing?

If the bottom cup bearing needs replacing, it is definitely a job that has to be done in a dry dock, but it should not be complicated or expensive, and it can be assessed whilst still in the water, by a feel round the bottom of the rudder stock and the cup, by an arm down the weed hatch.

 

That easy Eh?  I would have needed a 3ft arm with two elbows to achieve that on Helvetia. I had to get inside the counter and put my arm down the weedhatch to reach the prop shaft, the rudder bush was another 12" further down! and 15" further back

Edited by David Schweizer
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38 minutes ago, BEngo said:

On that basis I would expect the cup to be OK.

Try greasing the top and double check there is nothing fouling the rudder (go down the weedhatch and feel the front edge as far as you can).  If that doesn't cure it you will have to think about an out of water (or underwater if you know any divers) looking at.

Changing the top bearing should be easy, provided rust has not stuck all the bits together. Remove the rams head, then the bolts that hold the top bearing down, then pull the bearing and housing up and off the rudder stock.  Remove bearing from housing. Replace the bearing with a new one and the refit in reverse order. Hardest parts will be getting the rams head off, undoing the bearing bolts, removing the housing (take the paint off the stock), and getting the bearing out of its housing.:rolleyes:

N

Thanks so much. Given that the top bearings are only about £23, I think that’s certainly going to be the first plan. I think that I’ll also get in the water when it’s a bit warmer (yep... in my wetsuit) and also check out the rudder in more detail as suggested. 

 

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15 minutes ago, MaggieA said:

Thanks so much. Given that the top bearings are only about £23, I think that’s certainly going to be the first plan. I think that I’ll also get in the water when it’s a bit warmer (yep... in my wetsuit) and also check out the rudder in more detail as suggested. 

 

Do you have a "Liverpool" boat ? They have a different rudder set up to other makes

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12 minutes ago, MaggieA said:

Thanks so much. Given that the top bearings are only about £23, I think that’s certainly going to be the first plan. I think that I’ll also get in the water when it’s a bit warmer (yep... in my wetsuit) and also check out the rudder in more detail as suggested. 

 

Those top bearing units are usually well seized and rusted to the stock needing a hefty puller or wedges and sledge hammer or even oxy acetylene heat to remove it. Squirt penetrating oil around and leave it for a bit. The inner bearing track of the bearing unit should have visible on top around the sides 2 or 3 Allen head grub screws which secure it to the stock. If these are slackened right off, the stock with a bit of a tapping with a hammer on top with a wooden block MIGHT!! MiGHT! allow it to shift down a bit and settle down a little more into the cup on the skeg.

  • Greenie 2
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You need to use a water resistant grease such as stern tube grease, Castrol LM ( Lithium based hence the "L" ) is not water resistant and actually absorbs water, so will reduce the life of your bearing.

If you are fitting a new bearing avoid the cheaper Chinese option if you want it to last, I can buy inserts for these for around £5! Depending on the manufacturer, you can buy just buy the insert to fit your existing housing - measure the shaft size accurately as you may have english or metric .

You may need heat on the rudder stock taper boss if this was fitted hot or a bang with a lump hammer may suffice to free it when the nut is off.

Give all the bolts and bearing a soak with diesel to free rust and remove all paint etc from the shaft with abrasive cloth or tape. Before you undo the bearing bolts loosen the 2 grub screws in the bearing and lift the rudder up enough to remove rust/ paint on the shaft that is tight to the bearing. If you can, lift it enough rub out the grub screw indents from the shaft. It is often these marks that make removal difficult. If corrosion is bad then be prepared to split the cast iron housing and then the bearing, using a small angle grinder and thin cutting disc.

Most importantly do not shear the bearing mount bolts or studs off if they are tight. If they do not immediately undo, strike the bolt heads or nuts down to break rust in the thread. If this does not work then, if you have studs and nuts, carefully drill the nuts to split them. If you have bolts, cut the heads off with a grinder then soak the remaining thread with diesel and hopefully you can wind it out with grips or small stillsons

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On 16/01/2018 at 14:42, bizzard said:

Those top bearing units are usually well seized and rusted to the stock needing a hefty puller or wedges and sledge hammer or even oxy acetylene heat to remove it. Squirt penetrating oil around and leave it for a bit. The inner bearing track of the bearing unit should have visible on top around the sides 2 or 3 Allen head grub screws which secure it to the stock. If these are slackened right off, the stock with a bit of a tapping with a hammer on top with a wooden block MIGHT!! MiGHT! allow it to shift down a bit and settle down a little more into the cup on the skeg.

What Biz said... I have done this twice in the last five years with success both times.

 

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I have a bit of vertical play and in asimuth on the top bearing which appears to be a plain bearing ( no grease nipple). The boat is 1998 built. I must admit it doesnt overly concern me as it doesnt vibrate or create noise in any way. I think the rear weight of the rudder loads it in one biased position.  I,ll wait next blacking in 3 years and put it on my list of things to do. I cant see any reason it,ll come to harm as i,m assuming its a robust simple construction. Splash ! Oops famous last words !!

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