Rudder Problems - Where to Begin

[KeelsonGraham]

I'm stuck! I have a wobbly rudder and I don't know where to begin with either diagnosing the problem or rectifying it. I'm hoping someone might be able to offer some advice.

Last month returning to the UK on a 90 mile trip in benign conditions, the rudder started groaning and creaking occasionally. The noises quickly became louder and occurred every time the wheel moved. When I took off the emergency tiller plate I could see that the top of the rudder shaft was moving about ½ to ¾ inch. Some WD40 on the lower bearing solved the noise issue but I know I have to deal with the source of the problem.

The most obvious solution is to address the movement at the top of the shaft with sheet shims or a 3D-printed top shim, as per the advice on this forum. But I'm not sure if this is the complete solution. Does that much movement indicate that the lower hull bearing is shot and also needs replacing? What else in the rudder system should I be looking at?

[Jim Hardesty]

When I took off the emergency tiller plate I could see that the top of the rudder shaft was moving about ½ to ¾ inch.

A couple of questions.  Was the movement vertical or horizontal?  Except for the noise, did the boat steer normally? 

Shamrock (also a MKII) has a bearing/seal with screws in the top to tighten.  If it were mine I would verify that all was as the factory intended before any redesigning.  That is no broken or loose parts.
Jim
 

[KeelsonGraham]

Hi Jim, the movement is all horizontal. The boat steers just fine but the noise was concerning.

[scgunner]

Graham,

I had the same problem a lot of side to side slop. I never had much luck with silicone (I believe) shims though, I couldn't get them down very far and they were tight on the bottom and loose on the top. I went with the West Systems solution. They have a specific filler designed for just this problem. It involves drill holes in the fiberglass just below the tiller cap then with one of their syringes you inject the epoxy into that void. I did that about twenty years ago and it's worked very well for me, no slop.

[Ron Hill]

Keel : On my standard transom MK 1 I was able to stop the lateral rudder movement with cutting strips of Mylar drafting film and filling the void between the stainless rudder column and the PVC pipe that the column is in.

Not too sure about how you do that with a walk thru transom rudder column?? 

A few thoughts

[girmann]

You are lucky!

From my conversations with Catalina three years ago, there are replaceable bushings that are relatively inexpensive and moderately convenient to replace. You still have to drop the rudder, but the bushings are right at the top and bottom of the rudder tube. I can't seem to figure out how to attach a pdf to a post, once I figure that out, I'll do that.

I say you're lucky because even though I have a MkII, Catalina didn't change the rudder post design until well after Mola Mola was made. It has the old style rudder tube where your only resolution is the West System solution with graphite impregnanted epoxy. You coat the rudder stock in mold release, put the rudder back in the tube, and then inject rudder column with epoxy in three different places. Pray that you put on enough mold release so that there are no bare spots.

https://forums.sailinganarchy.com/threads/j36-rudder-bearings.67191/

The most obvious solution is to address the movement at the top of the shaft with sheet shims or a 3D-printed top shim, as per the advice on this forum. But I'm not sure if this is the complete solution. Does that much movement indicate that the lower hull bearing is shot and also needs replacing? What else in the rudder system should I be looking at?

[girmann]

Here's the pdf drawing that Catalina sent me. Yes, they are drawings for other Catalinas, but they assured me that this assembly exists on the MkII after 2001.

[KeelsonGraham]

Thank you all and thank you girman. That PDF is gold dust!

[girmann]

I talked to Warren Pandy at Catalina, if you have any questions, you could point your questions at them.

[KWKloeber]

West System solution with graphite impregnanted epoxy. You coat the rudder stock in mold release, put the rudder back in the tube, and then inject rudder column with epoxy in three different places. Pray that you put on  enough mold release so that there are no bare spots.

I did the graphite/epoxy fix - one of the best fixes I have done.

After waxing the stock just exercise the wheel until the epoxy kicks and there's no problem.
I didn't and the next day had a mild myocardial infarction when the rudder stock and tube were one non-moving part.  
A little persuasion freed it up. 

I even installed two zerk fittings thinking I'd lube it with waterproof grease.  I never have.