clunking noise from rudder post

[John R]

I have a 1998 Catalina 36. The last two sails, I've noticed a clunking noise coming from the rudder post. It is not a rythmic noise - only about once every 30 or 60 seconds or so. It only happens when I'm close hauled on a port tack (and only on the port tack) and when the boat is heeled over a fair bit. It might coincide with when the boat hits a swell, but I'm not sure. I looked up under the stern port lazarette while sailing and saw that the quadrant was moving up and down just a little bit - maybe 1/4 of an inch. I had a diver check under the water and he said that he didn't see any problem with the rudder, nor is the rudder loose on the post nor did he see any play in the post itself.

Today I went up in the aft cabin and looked back up under there. I found that the cable was quite loose. I am unable to tighten it because the nuts seem frozen, so I sprayed some PB blaster and will return in a day or two. Of greater concern is what I saw around the post. Take a look at the pictures. It looks to me like either the rudder post has dropped down or that a section of fiber glass encasing the post has pulled away and come down on the post.

What do you think?

 

[Afrakes]

It looks like the fiberglass used to support the upper bearing has come loose. How free is it? Can you slide it back up easily?

 

[John R]

Stupid me - I actually didn't try that. I'll go back tomorrow and give that a try.

Question: If I can slide it back up the post, what do I do then? How can I fix it up there/prevent if from sliding back down again?

 

[dlochner]

Well, something certainly ain't right.

Can you get a shop drawing from Catalina that shows how the rudder post was designed? That will give you clues about how it should be.

There is a lot of fiberglass dust on the steering quadrant, that is concerning.

Unfortunately, I think this may be difficult to repair with the rudder in place and the boat in the water.

 

[Afrakes]

Your quadrant rides high above the rudder post gland. What holds the rudder up when the boat is out of the water. Open the access to the top of the rudder post and see what's going on there. That's a pretty thin skin of fiberglass separated from the under side of the cockpit. Check out the tech details as dlochner suggested to get a clear picture of how things are supposed to be.

 

[John R]

What is weird is this: Although you can barely see it from the photos, it looks as if the quadrant is high based on how the cable runs. In other words, as the cable runs forward on the quadrant, it actually rubs against the bottom of the groove in the quadrant.

But anyway, on Monday I will call Catalina and see if I can get a schematic or something. And I guess the quick fix I had planned is out of the question. My idea was to see if I could slide that fiber glass up the post and glue in place with 5200, maybe turning the rudder after about a half hour to make sure the post doesn't get glued to the fiber glass. But I think that's probably too mickey mouse. I'll take a look from above tomorrow to see what I can see from there.

 

[Meriachee]

glue in place with 5200

Really? Seriously? I wouldn't say that in a public forum where your insurance company might trip over it.

 

[Franklin]

I had the same thing on my Hunter 376. In my case, it was a plastic separator/spacer worn out (uneven ware) between the rudder and the hull. Nothing like hearing a knocking noise from the cockpit floor when you are 1500 miles form the nearest land.

As the rudder would turn, the quad would rise and then if it turned far enough, it would "pop" back down. In my case, the sound would echo all over the place so I could only find the problem by feel. 3 am I have my hands stretched out, feet stretched out all trying to "feel" something when the sound would come, but sometimes it wouldn't come for 20 minutes so waiting and waiting wishing I was plastic man I thought it was the rudder bearings until I got the boat on the hard and dropped the rudder.

 

[kloudie1]

If ya have top access, you could make two half circular plates (maybe 1/8" aluminum) to use as backing plates for the little fiberglass collar. Pull the collar up against the top "floor" and thru-drill about 8 holes then insert bolts from the top and snug the plates up, sandwiching the little collar's flange and securing it to the bottom of the floor. Would require moving the quadrant down temporarily to get access.

 

[Afrakes]

My observation of your quadrant riding high is in comparison to mine which is immediately above my rudder post gland. Between the gland and quadrant there is a nylon washer which bears the weight of the rudder. There is also a nylon washer between the top of the rudder and the hull. The up and down play is a small fraction of an inch.

 

[John R]

My observation of your quadrant riding high is in comparison to mine which is immediately above my rudder post gland. Between the gland and quadrant there is a nylon washer which bears the weight of the rudder. There is also a nylon washer between the top of the rudder and the hull. The up and down play is a small fraction of an inch.

I suspect yours is a different set-up. If my quadrant were that low, it would be way too low.

 

[John R]

Here are some additional pictures. The first one is of the pulleys that lead the cable to the quadrant. I suspect that the noise I was hearing was from the cable being way too loose, which gave too much side-to-side play in the wheel of the pulley. I also suspect that the noise is a different issue from what else I saw. The second picture is taken from the deck with the deck plate removed. The third is a close-up of what I'm seeing from below. I was able to slide that part that's come loose up towards the bottom of the deck, but not all the way up. I think I might have to break down and have a yard take a look at this. It may be beyond my job description and loosing a rudder is a "little" more than I want to risk.

 

[Franklin]

My suggestion is to have your boat hauled out. It is a very good possibility that your rudder floats like mine. If it does, that means there is a uneven worn out spacer that is allowing the rudder to ride up higher than it is supposed to be. These spacers are made of UHMW (Ultra-high-molecular-weight polyethylene) but Teflon can work too. They wear out in time and need to be replaced. When they do, when the rudder turns to an uneven thinner section the rudder post will ride up higher and reach areas it is not supposed to. That is where your knocking sound is coming from.

 

[Afrakes]

From the pictures it appears that your rudder is supported by the upper bearing. The collar on the outside of the rudder tube rests on the upper bearing. The support for the upper bearing has failed and that is allowing the bearing to slide downward leading to the up and down play in the rudder. Pull the boat, drop the rudder, take precise measurements, raise the upper bearing and rebuild its support, get some spacers for between the top of the rudder and hull and between the support collar and upper bearing and reassemble. All within the talents of a DIYer.

 

[John R]

So, here's the latest on this issue:

I contacted Catalina. The guy I spoke with (Warren) seemed to think that the collar itself had come away and that all I needed to do was to raise it back up to the underside of the deck there and fix it in place. I did that with 5200 plus some screws. (See photo #1.) Before, it was only fixed in place with a single layer of fiver glass, so I think it's at least as strong. One thing that concerns me a little is the fact that the sketch that they sent me shows the collar down below the top of the post. (See photo #3.) On mine, it is exactly flush. (See photo #2) I was worried that this meant that the post had, in fact, dropped down. (Warren assured me that this was impossible unless I'd hit something with the rudder, which I haven't done to my knowledge.) I suspect that it's just an anomaly in the drawing, for this reason: Given how that bolt fits through the collar and the post, if the post were raised it would mean that the collar would have to be above the nylon bushing rather than resting on it, which is exactly what it's doing right now.

I took the boat out the other day and among other things the knocking noise wasn't there. I don't know what caused it - maybe that the cable was very loose and was causing the pulley to shift from side to side on a port tack.

Thanks again to everybody for their comments and any further ideas are appreciated.