How often should I grease the stern bearings?

[Alan de Enfield]

2 minutes ago, eid said:

 

Yes, I think I will!

 

I noticed he used some sealant around it. Is it anything special?

If they didn't know to put the nipple at the side, I'd suggest they just used some 'silicone sealer' from Poundland (or similar)

 

 

[Tony Brooks]

If the bearing accepts grease with the nipple in the front then fine but if it appears to be blocked but is not full of hard grease then putting the nipple on the side IN SOME DESIGN OF BEARING might help. In other  designs the hole in the case is large enough or made elongated in the vertical plane so the nipple can be at the front.

[Tony Brooks]

49 minutes ago, pete harrison said:

I can not understand the need for a bearing to centralise the rudder post.

 

I am more familiar with 'historic' narrow boats where just like modern boats the bottom of the rudder post is supported by a cup and skeg arrangement. Just like modern boats the rudder post then passes through the depth of the counter via a tube, with the rudder post and 'Z' shaped Rams Head bolting together a few inches above the deck. The big difference is that on a 'historic' boat the rudder post is supported in a central position (in relation to the rudder tube at deck level) by a flanged collar that that simply drops into the rudder tube and has a hole in its centre that is a little larger diameter than the rudder tube - very simple and very effective.

 

To my untrained eye the only benefit of a bearing at deck level is the prevention of water coming onto the deck via the rudder tube, which happens occasionally when the rudder is hard over combined with highish engine revs. Also to my untrained eye this bearing will always be subjected to standing rainwater and dirt so will always be liable to failure.

 

It appears to me that the old ways are the best, or am I missing something

I suspect the use of a bearing that is usually some form of self aligning bearing is to do with the rudder tube being set at an angle to the rear "deck". That could be accommodated by the said flanged collar IF the center hole was bored at an angle to the vertical to suit the angle of the rudder tube. It would still work if the hole was oversize but then as there would only be a small contact area between the rudder stock and flange at the front and back it would wear quickly.

 

However you my mean the rudder tube stands proud of the stern "deck" with both the tube and flange set at an angle to the deck. That would work but perhaps it is not aesthetically acceptable to some.

[pete harrison]

2 minutes ago, Tony Brooks said:

I suspect the use of a bearing that is usually some form of self aligning bearing is to do with the rudder tube being set at an angle to the rear "deck". That could be accommodated by the said flanged collar IF the center hole was bored at an angle to the vertical to suit the angle of the rudder tube. It would still work if the hole was oversize but then as there would only be a small contact area between the rudder stock and flange at the front and back it would wear quickly.

 

However you my mean the rudder tube stands proud of the stern "deck" with both the tube and flange set at an angle to the deck. That would work but perhaps it is not aesthetically acceptable to some.

I suspect re-aligning a rudder that has come out of the cup / skeg would be a nightmare with that bearing in the way, or does the bearing hold everything in line so it can only fall back into the cup ?

[Tony Brooks]

1 minute ago, pete harrison said:

I suspect re-aligning a rudder that has come out of the cup / skeg would be a nightmare with that bearing in the way, or does the bearing hold everything in line so it can only fall back into the cup ?

I suppose that depends upon how much clearance there is between the stock and tube. There is a real danger of lifting the rudder out of the skeg if you cill the rudder going down - then the fun begins. I have seen the RCR bods drop a displaced rudder back into the skeg is a very few minutes but it too me a long time when I tried to help another boater do it. I suppose it depends on practice. It is not helped by the weight of the whole assembly that ha s be lifted.

 

Being a self aligning bearing it in no way holds the stock so it drops straight back into the skeg unless you are very lucky. However there seem to eb a host of designs, some use a top bearing of varying types and some do not.

 

[pete harrison]

3 minutes ago, Tony Brooks said:

I suppose that depends upon how much clearance there is between the stock and tube. There is a real danger of lifting the rudder out of the skeg if you cill the rudder going down - then the fun begins. I have seen the RCR bods drop a displaced rudder back into the skeg is a very few minutes but it too me a long time when I tried to help another boater do it. I suppose it depends on practice. It is not helped by the weight of the whole assembly that ha s be lifted.

In my experience getting a rudder back into the cup is a combination of two things - a little bit of judgement and an awful lot of luck, and the weight of a rudder assembly on a modern boat is considerably less than that on a 'historic' boat although the principle is identical

[Scholar Gypsy]

4 hours ago, pete harrison said:

I can not understand the need for a bearing to centralise the rudder post.

 

I am more familiar with 'historic' narrow boats where just like modern boats the bottom of the rudder post is supported by a cup and skeg arrangement. Just like modern boats the rudder post then passes through the depth of the counter via a tube, with the rudder post and 'Z' shaped Rams Head bolting together a few inches above the deck. The big difference is that on a 'historic' boat the rudder post is supported in a central position (in relation to the rudder tube at deck level) by a flanged collar that that simply drops into the rudder tube and has a hole in its centre that is a little larger diameter than the rudder tube - very simple and very effective.

 

To my untrained eye the only benefit of a bearing at deck level is the prevention of water coming onto the deck via the rudder tube, which happens occasionally when the rudder is hard over combined with highish engine revs. Also to my untrained eye this bearing will always be subjected to standing rainwater and dirt so will always be liable to failure.

 

It appears to me that the old ways are the best, or am I missing something

I agree this is what I have on my boat.  Very simple. 

[eid]

13 hours ago, Tony Brooks said:

If the bearing accepts grease with the nipple in the front then fine but if it appears to be blocked but is not full of hard grease then putting the nipple on the side IN SOME DESIGN OF BEARING might help. In other  designs the hole in the case is large enough or made elongated in the vertical plane so the nipple can be at the front.

Ah, thanks Tony. I'll give that a try.

[Matthew77]

Owners manual on my LB says once a year. Did mine last week made a huge difference.

[ditchcrawler]

On 30/09/2018 at 19:46, Tony Brooks said:

I suppose that depends upon how much clearance there is between the stock and tube. There is a real danger of lifting the rudder out of the skeg if you cill the rudder going down - then the fun begins. I have seen the RCR bods drop a displaced rudder back into the skeg is a very few minutes but it too me a long time when I tried to help another boater do it. I suppose it depends on practice. It is not helped by the weight of the whole assembly that ha s be lifted.

 

Being a self aligning bearing it in no way holds the stock so it drops straight back into the skeg unless you are very lucky. However there seem to eb a host of designs, some use a top bearing of varying types and some do not.

 

I have only done it once, on a hire boat we were following, not sure how he displaced it but it dropped back in one. I had to buy a bigger hat after that

[system 4-50]

Dear Agony Aunt,  I have had my boat for nearly 8 years, is it time I scraped the original paint off the grease nipple on my rudder bearing and used a grease gun on it? Yours, clueless.

PS Are nipples standard sizes and will any gun work? C.

[Tony Brooks]

8 hours ago, system 4-50 said:

Dear Agony Aunt,  I have had my boat for nearly 8 years, is it time I scraped the original paint off the grease nipple on my rudder bearing and used a grease gun on it? Yours, clueless.

PS Are nipples standard sizes and will any gun work? C.

 

I have seen a number of different designs over the years but the ones on typical rudder bearings  all seem to be the standard nipple and any decent grease gun should fit.

[Alan de Enfield]

9 hours ago, system 4-50 said:

Are nipples standard sizes

If you use google images and enter  'nipples' you will see that yes, there are a variety of sizes.

[WotEver]

8 hours ago, Alan de Enfield said:

If you use google images and enter  'nipples' you will see that yes, there are a variety of sizes.

I just tried it. You’re  absolutely correct.