Tiller bearing, Liverpool Boat 2005

[BEngo]

4 minutes ago, blackrose said:

 

I'm measuring the shaft diameter as 1.276" or 32.4mm

Allowing for a bit of rust, and the draw tolerance when the stock was made I would say you have an imperia 11/4 inch stock, or at least an imperial bearing when the scousers finished it.

 

N

 

 

 

[ditchcrawler]

20 minutes ago, blackrose said:

I'll measure the shaft but surely there needs to be a gap of a 1 mm or 1.5mm on each side? That's all there is in my case. If there was no gap you'd struggle get the shaft into the bearing. It can't be an exact fit. 

A bearing should be an interference fit on the shaft

[BEngo]

 

2 minutes ago, Tracy D'arth said:

A CV joint boot over the bearing is best but means taking the swan neck off.

I agree, but I expect he is due back afloat soon and the rams head and blade are welded to the stock....

[reg]

1 hour ago, blackrose said:

 

It's exactly the same diameter as the one I took off. 35mm.

 

Can I shim the back of the rudder stock between the bearing and stock? 

Just to confirm mine was a 2005 liverpool shell and the replacement bearing was 35mm from Ebay. refitted 35mm bearing no problem.

 

 

 

[Tracy D'arth]

1 hour ago, blackrose said:

 

It's exactly the same diameter as the one I took off. 35mm.

 

Can I shim the back of the rudder stock between the bearing and stock? 

Have you tried turning the inner race 180 degrees?  Your rudder tube must be very small or not in line if it is touching. Will the bearing move around the bolts to give you some clearance? If it was fitted with the  wrong bearing from new there must be some clearance somewhere by shifting things around.

[Awayonmyboat]

As just use a bit of shim (a sliver of a can or similar) to centralise the stock. On my boat I found the grub screws frequently loosened - a drop of Loctite solved that.

[blackrose]

3 hours ago, BEngo said:

It is definitely too big, you can see the gap in the pic.  

 

Yes the gap is 1.3mm on each side. That's the same as it's been for the last 17 years. 

3 hours ago, BEngo said:

Try turning the inner race through  180 so the grub screw is at the back, then tighten up the screws.  You may need some longer ones. If not some thick shims may be OK.  Like the pinch bolts they will not like vibration much and will need regular tightness checks and renewal.  If using shims make sure you don't  have pointed grub screws in the bearing.  Dog point or cup point are what you want.

 

If not you need a bush, which will have to be split into two to get it in without dismantling. OD 35 mm ID about 1mm bigger than the shaft.

 

As far as grease goes put some waterproof grease in.  The bearing fitted has a metal seal !(suffix Z or ZZ  on the bearing number) which is not watertight.  The current fit also has a handy water trap on top.  It would be worth filling that with grease if the potential mess is acceptable, or providing a rubber cover ( disc of car mat with a shaft sized hole and a knife cut to the centre so you can fit it.

 

N

 

I tried turning grub screws so they're at the back but that was even worse. They're cup point screws. 

[blackrose]

3 hours ago, Tracy D'arth said:

A CV joint boot over the bearing is best but means taking the swan neck off.

 

I've never understood the idea of covering the bearing from above to stop water getting in as water comes up from below through the rudder tube. 

3 hours ago, BEngo said:

Allowing for a bit of rust, and the draw tolerance when the stock was made I would say you have an imperia 11/4 inch stock, or at least an imperial bearing when the scousers finished it.

 

N

 

No, as I said, it was a 35mm bearing, same as the one I've just fitted 

3 hours ago, ditchcrawler said:

A bearing should be an interference fit on the shaft

 

So what are the grub screws for? A proper interference fit shouldn't really need additional fixings. 

 

[blackrose]

4 hours ago, BEngo said:

 

I agree, but I expect he is due back afloat soon and the rams head and blade are welded to the stock....

 

No they're not welded. I'm coming back here in a year for the yard to finish grit blasting my swims and uxter plates. They overestimated the capability of their equipment. But anyway I'm not going to use a CV boot. It's pointless in my opinion. If anything it will just trap the water coming up from the rudder stock tube and prevent it evaporating.

 

3 hours ago, reg said:

Just to confirm mine was a 2005 liverpool shell and the replacement bearing was 35mm from Ebay. refitted 35mm bearing no problem.

 

 

 

 

Thank you. I knew I wasn't going mad. I think what I've done is locate the bearing in a forward position in order to align it with the rudder tube, but perhaps it's off centre. 

 

3 hours ago, Tracy D'arth said:

Have you tried turning the inner race 180 degrees?  Your rudder tube must be very small or not in line if it is touching. Will the bearing move around the bolts to give you some clearance? If it was fitted with the  wrong bearing from new there must be some clearance somewhere by shifting things around.

 

Yes I've tried turning the inner race. 

 

2 hours ago, Awayonmyboat said:

As just use a bit of shim (a sliver of a can or similar) to centralise the stock. On my boat I found the grub screws frequently loosened - a drop of Loctite solved that.

 

Thanks. I'll do that. 

Edited August 9, 2022 by blackrose

[blackrose]

19 hours ago, BEngo said:

As far as grease goes put some waterproof grease in.  The bearing fitted has a metal seal !(suffix Z or ZZ  on the bearing number) which is not watertight.  

 

I just called the bearing supplier who told me the stainless bearing is pre-greased and sealed for life. Apparently the grease nipple allows you to put grease between the housing and the outside of the bearing to facilitate 8 degrees of movement. I assume that's the vertical shaft movement? 

[Tracy D'arth]

Most of these angular adjustable bearings have no greaser hole in the outer race. The grease nipple does, as blackrose says, only grease the spherical alignment surfaces in the housing.

To prevent water entering the bearing from below, a purpose cut tight fitting rubber washer in the rudder tube is a good idea along with a cover of some sort on the top of the bearing.

[blackrose]

Do you think a sealed for life bearing will resist water coming up under pressure from the rudder stock tube? 

[BEngo]

So, in the boat set up,  the grease nipple is of  the chocolate teapot family.

 

The supplier is correct- the bearing is greased for life.  That life is expected to be in a reasonably well protected location under specified load conditions.  It will be a short life in a location where the bearing frequently gets drenched in turbid water from one side and sits in a puddle of rainwater on the other side.  It will last longer if if gets some fresh grease occasionally. As soon as the bals rust it is terminally damaged. The metal seals usually  just flip out with a small screwdriver, and go back as easily.

 Tracy's suggestion of a rubber washer at the base of the rudder tube is a good one.  It benefits even things like old working boats where the bearing arrangements tend to be quite crude.

N

[Tracy D'arth]

2 minutes ago, blackrose said:

Do you think a sealed for life bearing will resist water coming up under pressure from the rudder stock tube? 

On its own, no.

When I install these flanged bearings on rudder shafts I always install a rubber washer in the tube and leave a gap between the bearing lower face and the deck mounting so that there is no pressure in any water forced up the tube that cannot escape before it gets to the bearing.

[blackrose]

I'm just wondering how I'd get a washer to fit? I could trim the tube overhang down by 5mm when the boat comes out again next year and fit a big o-ring between the top of the rudder and the tube?

 

7 minutes ago, Tracy D'arth said:

On its own, no.

When I install these flanged bearings on rudder shafts I always install a rubber washer in the tube 

 

I don't think I've got enough clearance to fit a rubber washer between the shaft and tube if that's what you mean? It would just get mashed up as soon as I turned the tiller. 

[Tracy D'arth]

I fit it from the top. Just a washer cut from thick re-enforced rubber sheet, rammed into the tube with a close fit on the shaft. It soon wears in and produces a surprisingly good seal. Water should only try to come up the tube when in reverse with a fair bit of power on.

Leaving a space under the bearing lets the water out onto the deck before it reaches the bearing.

 

That tube is extremely small, I am not surprised that you have clearance problems. Most are a god bit bigger than that.

[BEngo]

You want a disc of a rubber that is quite stiff and just  large enough that it does not flop down either side of the rudder blade.  Redundant car floor mats are a good source of suitable stuff.

 

The hole in the middle wants to be a close, near tight fit on the stock. You ram the stock in as you reassemble.

 

 

You are not worried if the disc is being forced down as that means the water is going down and thus is not going up the tube.  On the other hand, with water going up,  the disc goes with it and seals the bottom of the tube.

 

N

[blackrose]

I've fitted this as a temporary measure. It might come off. I'll fit one without a cable tie over the shaft next year.

 

 

 

A washer or o-ring between the rudder stock and tube would never work in my case. There's not enough clearance and anything you could get between them would soon get broken and be forced out by the water pressure coming up the tube. 

Edited August 10, 2022 by blackrose

[adrianh]

 I bet if you clean all the rust of with emery tape the shaft will come up at 1.250 inch diameter.

Unfortunately you have bought a bearing with a dust proofing seal that will allow water into the ball elements, also unless you have anything to stop the ingress of water on the outside ring of the bearing, even with copious amount of grease being added, the bearing will have a reduced life.

Don't forget also that the lower face is totally open to damp. 

If this is a cheaper chinese brand then it is very likely that the balls inside the bearing are standard steel so will corrode.

If you decide to buy a better fitting bearing then just purchase a standard non stainless insert, to fit your housing, with rubber seals, you will find it is likely to last longer than stainless.

My work takes me into food factories, the poor life of stainless versus standard bearings often means that the inserts are replaced as above.

 I bet if you clean all the rust of with emery tape the shaft will come up at 1.250 inch diameter.

Unfortunately you have bought a bearing with a dust proofing seal that will allow water into the ball elements, also unless you have anything to stop the ingress of water on the outside ring of the bearing, even with copious amount of grease being added, the bearing will have a reduced life.

Don't forget also that the lower face is totally open to damp. 

If this is a cheaper chinese brand then it is very likely that the balls inside the bearing are standard steel so will corrode.

If you decide to buy a better fitting bearing then just purchase a standard non stainless insert, to fit your housing, with rubber seals, you will find it is likely to last longer than stainless.

My work takes me into food factories, the poor life of stainless versus standard bearings often means that the inserts are replaced as above.

 

Edited August 10, 2022 by adrianh
Text duplicated when posted

[adrianh]

All these bearings have a radial groove around the outer perimeter of the insert so that they can be regreased ( unless yours is a very cheapo type).

As this is not a rotating bearing ( as it would be industrially ) I would use stern tube grease. This is water resistant unlike the lithium grease that this bearing will be pre loaded with.

In an industrial enviroment for a prolonged life they are normally greased regularly.

Sealed for life = sealed for a reduced life = premature failure

[blackrose]

35 minutes ago, adrianh said:

 I bet if you clean all the rust of with emery tape the shaft will come up at 1.250 inch diameter.

Unfortunately you have bought a bearing with a dust proofing seal that will allow water into the ball elements, also unless you have anything to stop the ingress of water on the outside ring of the bearing, even with copious amount of grease being added, the bearing will have a reduced life.

Don't forget also that the lower face is totally open to damp. 

If this is a cheaper chinese brand then it is very likely that the balls inside the bearing are standard steel so will corrode.

If you decide to buy a better fitting bearing then just purchase a standard non stainless insert, to fit your housing, with rubber seals, you will find it is likely to last longer than stainless.

My work takes me into food factories, the poor life of stainless versus standard bearings often means that the inserts are replaced as above.

 I bet if you clean all the rust of with emery tape the shaft will come up at 1.250 inch diameter.

Unfortunately you have bought a bearing with a dust proofing seal that will allow water into the ball elements, also unless you have anything to stop the ingress of water on the outside ring of the bearing, even with copious amount of grease being added, the bearing will have a reduced life.

Don't forget also that the lower face is totally open to damp. 

If this is a cheaper chinese brand then it is very likely that the balls inside the bearing are standard steel so will corrode.

If you decide to buy a better fitting bearing then just purchase a standard non stainless insert, to fit your housing, with rubber seals, you will find it is likely to last longer than stainless.

My work takes me into food factories, the poor life of stainless versus standard bearings often means that the inserts are replaced as above.

 

 

There's really not that much rust on the rudder stock. In my experience not much stops water getting into these bearings whatever you try to do. I don't really understand why you think stainless is more susceptible to corrosion than mild steel? I also work in food factories and in my experience it's the opposite. We use stainless bearings on all our equipment.

 

22 minutes ago, adrianh said:

 

Sealed for life = sealed for a reduced life = premature failure

 

We will see. The old standard bearing didn't last long and wasn't really doing anything after about a year. 

Edited August 10, 2022 by blackrose