Rudder stiff to one side

[sundanceoflorn]

Hoping for some advice after investigating stiff full skeg rudder on my Tyler 34 today. It is more apparent to starboard - from centreline to port seems okay - this is after removing the quadrant and pushing the rudder with one finger.

The helm has been noticeably stiffer last 2 years. I did bottom out when tied to a pontoon and the bottom of the skeg and back of the rudder were on the sea bed as it sloped slightly behind the keel although I am not sure if there was much pressure as it was sand.

There is no obvious sign of cracking or misalignment I can see. I removed the packing from the gland - there were 6 rings black with old grease and 30 years old. The rudder squeaked when moved but I traced that to the fitting in the brass shoe where the bottom of the rudder stock sits. Lifting the rudder up slightly stopped it so I put some grease in and now no squeak. I noted that I could lift the rudder up that way easily except when it was over to starboard. Both these have made some improvement.

I wanted to drop the rudder to see if there are bearings - all I can see is what looks like a nylon bush at the end of the rudder tube where it exits the hull. The problem is that the brass shoe seems to be riveted to the skeg - there are 5 smooth heads either side with no nut or screw head to undo (see photo)


I wondered about removing the packing gland at the top to see if there was access to bearings below but it fits over the fibreglass tube that surrounds the rudder tube and is tight and I didn't want to force it as expect is watertight (see photo).

There is hardly any play in the rudder as the bottom shoe fitting is tight fitting and no noise to indicate bearing failure. Any advice on how to proceed or if I am worrying about nothing appreciated

 

[Tranona]

The only way to find out is to drill out those copper rivets and remove the shoe and check the bearing inside. It may be a bronze bush or a composite bearing such as acetal. The fact that you have difficulty lifting it when on starboard suggests that there may be some uneven wear there. Replace the copper rivets with bronze bolts - not so elegant but much easier to get tight.

 

[vyv_cox]

Not the same boat, nor even the same problem, but you may find this page useful. Sadler 34 and 32 rudder bearings

 

[neil_s]

I have a similar problem with my tiller steered Seal 28. I found a good squirt of PTFE lube in the bottom shoe and down the top of the rudder shaft made a great improvement!

 

[penberth3]

I have a similar problem with my tiller steered Seal 28. I found a good squirt of PTFE lube in the bottom shoe and down the top of the rudder shaft made a great improvement!

It might make an improvement, but it doesn't diagnose the problem!

I'd suspect something is slightly bent. The OP does say he'd grounded at some stage.

 

[sundanceoflorn]

Hi All thanks very much for all the advice so far. Tranona's response gave me the confidence to drill out the copper rivets today and I dropped the rudder. There are acetal bearings in the shoe and where the rudder post enters the tube. The shoe one looks similar to the top hat shaped one in the Sadler article (thanks for that!) but the surface of it is lower than the surrounding shoe surfaces - see below. I wonder if this is why it was squeaking as maybe it should be proud of that and has worn down? This would explain the 1cm or so of the shaft visible between the top of the rudder blade and the hull.

The top bearing is about 4cm high and has a grooved channel halfway up on the inside - see below. Above the groove is black with grease but is same material as below and I think there is a metal ring above that to stop the bearing going further up. It is flush with the lower end of the tube

I think there is a bit of uneven wear although if I wasn't looking for it would not be obvious. In any case replacing both seems sensible - they are totally rigid so left in situ for now until I find replacement then think they will need cut out.

The rudder stock itself looks straight to my eye - not sure if there is a more scientific way to check? Some scarring on the surface where it is in contact with the top bearing.

Above the top bearing it is just fibreglass tube then the gland and no obstructions.

Not sure how I can identify and source these bearings so any further knowledge and advice most welcome thanks

 

[LittleSister]

The rudder squeaked when moved but I traced that to the fitting in the brass shoe where the bottom of the rudder stock sits. Lifting the rudder up slightly stopped it so I put some grease in and now no squeak. I noted that I could lift the rudder up that way easily except when it was over to starboard. Both these have made some improvement.

Sounds to me like a bent rudder shaft (or perhaps some other misalignment of the upper parts, rather than the shoe).

Perhaps under a grounding, or serious side loading (which can be a surprisingly high), the skeg etc. flexed elastically, while the shaft has suffered plastic deformation (or some other upper part damaged or forced out of proper alignment).

I think the squeaking is not the root of the problem, and is either a red herring, or the result of a misalignment putting more load, and displacing the grease, on one side.

I don't know, of course, but my advice would be not to spend too long 'looking at your shoes'! I suspect the squeaking etc. down there is an indication of a problem elsewhere.

The key question is whether (having re-lubricated the lower bearing) the rudder being stiffer on one side is a serious problem (i.e. is causing stress with the potential to break or damage something), or is just a mild irritation that could be lived with.

Good luck.

 

[Tranona]

Not sure how I can identify and source these bearings so any further knowledge and advice most welcome thanks

The bearings were almost certainly made to measure - not difficult for a machine shop with experience of machining Acetal (Delrin is the most common brand). Normally (at least when I made a rudder and shoe) the pintle coming out of the bottom of the rudder had a bearing surface that runs on the top hat part of the bearing, although that is not essential. Check the bearing for concentricity - stiffness one way may indicate the bearing has worn oval. Acetal is water lubricated so does not need greasing. The bottom bearing in the one I made went 20 years without any wear. I had a spare made at the same time which made a nice desk ornament!

 

[Findhorn]

I would take a long hard look at the integrity of the skeg...just saying

 

[sundanceoflorn]

I would take a long hard look at the integrity of the skeg...just saying

Thanks Findhorn - I dug out the full condition survey I had done last year and has this:
11.2. The rudder was a full skeg hung unbalanced rudder. The rudder was manually force tested and found to be secure. There was no discernable vertical movement or lateral movement. There was ~2mm of fore and aft play in the heel bearing.
11.3. The skeg was integral to the hull moulding. The skeg was manually force tested and found to be secure. Internal inspection of the skeg was not possible because of access through the carpeted sole in the aft cabin.

I guess the force testing would be to see if there was any flex - do you have anything else in mind regarding the integrity and how to check?

 

[sundanceoflorn]

The bearings were almost certainly made to measure - not difficult for a machine shop with experience of machining Acetal (Delrin is the most common brand). Normally (at least when I made a rudder and shoe) the pintle coming out of the bottom of the rudder had a bearing surface that runs on the top hat part of the bearing, although that is not essential. Check the bearing for concentricity - stiffness one way may indicate the bearing has worn oval. Acetal is water lubricated so does not need greasing. The bottom bearing in the one I made went 20 years without any wear. I had a spare made at the same time which made a nice desk ornament!

I am down the road now and have the shoe here - it does look pretty circular. What I have noticed though is that there does look to be downwards wear on the acetal and maybe 1mm to one side as one surface of the recess where it sits is clean (left side below) and the opposite side has a small remainder of acetal.


The surveyor noted that there was ~2mm of fore and aft play in the heel bearing. I am wondering if the squeaking was the side of the shaft rubbing on the brass on that bare side. It also might indicate that the acetal was originally flush with the top of the recess or even proud, or maybe there was an acetal disc on the bottom of the shaft similar to how you mentioned the acetal round the pintle so that both binding surfaces are acetal?

I had actually asked the surveyor to look at the stiff steering as there was also a noise from the quadrant and he discovered that this was actually the bottom of the quadrant rubbing on the top of a bolt hidden underneath and raising the quadrant slightly resolved this. So the acetal wearing down the way may explain how that came about as the whole rudder tube would drop.

Don't think its the full story but either inserting an acetal disk there or making the new bearing proud of the recess may assist

 

[sundanceoflorn]

Sounds to me like a bent rudder shaft (or perhaps some other misalignment of the upper parts, rather than the shoe).

Perhaps under a grounding, or serious side loading (which can be a surprisingly high), the skeg etc. flexed elastically, while the shaft has suffered plastic deformation (or some other upper part damaged or forced out of proper alignment).

I think the squeaking is not the root of the problem, and is either a red herring, or the result of a misalignment putting more load, and displacing the grease, on one side.

I don't know, of course, but my advice would be not to spend too long 'looking at your shoes'! I suspect the squeaking etc. down there is an indication of a problem elsewhere.

The key question is whether (having re-lubricated the lower bearing) the rudder being stiffer on one side is a serious problem (i.e. is causing stress with the potential to break or damage something), or is just a mild irritation that could be lived with.

Good luck.

Thanks LittleSister noted. There isn't any grease/lubrication for acetal bearings but the above finding that the rudder shaft is slightly over to one side may be misalignment or just wear on the lower part of the bearing allowing it to move left and right a bit - surveyor noted ~2mm play.

Is there any way to check for misalignment? I though of getting some plastic tube 40mm inside diameter and seeing if this fitted smoothly over the exposed part of the rudder shaft but then there is the majority part inside the rudder.

I could live with it - my main concerns that it could seize or fall off are unwarranted I think having understood how it fits together, but I would like to resolve now that its off, unless that means a new rudder

 

[vyv_cox]

The upper photo in your post #6 and the view in #11 both suggest that a thrust washer is missing. It is quite common for these to wear down until they crack and fall away. Mine on my Sadler was like that, I could lift the rudder 10 mm from the shoe, no washer at all. Other Sadlers had one, so I made the new bearing top hat style to provide a thrust face.

 

[Tranona]

That is the way I did mine but had a stainless washer welded onto the shaft to provide the bearing surface of the rudder. Also made it easier to get a good seal for the wood epoxy rudder against the shaft.

For the OP. If the bottom of the rudder and pintle have a good solid bearing surface I would be tempted to have a washer mad with maybe 3mm thickness showing above the shoe.

 

[sundanceoflorn]

Thanks a lot both - I knew I had read about thrust washers somewhere the last couple days and realised it was your link vyv_cox! I like the idea of the top hat (thrust collar instead of washer) as may be less likely to crack if not moving. There is also an 8mm face surrounding the recess that would support this. Looks about 2mm recess so could have the collar 3mm thick as Tranona suggests which will lift it 5mm and there should still be a 5mm (or more) gap between the hull and the top of the rudder. I'll measure that clearance - think its recommended to have some gap there to allow water to flow over the bearing. I don't think there is a need for a collar or washer at the top if the rudder stock is on the shoe unless it could ride up which the quadrant should prevent.

The grooves on the outside face of the bearing to allow epoxy a good idea as was wondering what stops the bearing coming out especially the top one which is totally solid - think I'll need to cut a slot in it to get it out.

Any idea what the groove round the inside of the top bearing is for (2nd photo in post #6)? Wondered about grease but then there shouldn't be any

 

[DinghyMan]

Groove is possibly an oil seal to stop any water travelling up the rudder stock

Grease is not a problem, or a requirement, for Acetal or Delrin bushes & bearings

 

[sundanceoflorn]

Thought I'd update progress on this and also a couple of questions as advice has been very useful so far.

I have cut the bearings out and found that that photo in #11 above is already a top hat bearing - brim about 6mm thick. I thought the ring outside the recess was actually part of the brass shoe but was just very dirty! So there is a 2.6mm recess in the acetal. I thought this had just worn through but the company I am getting new bearings made at have suggested it may be an intentional recess to seat the shaft. Is that something you have seen? And if there had been a thrust washer then guess it would be recessed top side and protrude the bottom side for same reason

Second question is on the bronze bolts Tranona suggested instead of the copper rivets. I am a bit wary that the sides of the shoe are curved so it is not a flat surface for the hex head and washer/nut but may be unwarranted. The copper rod measures as 10mm but I can only seem to find 3/8" on the Internet so not sure if they are actually 3/8" to get correct bolts without being at the boat and trying for size as want a tight fit. If you know any good companies that supply either would appreciate recommendation. I am guessing the length should be distance through the shoe + 10mm for the washer/nut to screw on.