Should my rudder do this?

[robertsapp]

I'm curious about the fact that our rudder has about a half inch of vertical play. We noticed when we hauled the boat as part of the pre-purchase survey that there was a "bald spot" on the bottom of the hull above the rudder. It looked like the rudder had worn off the bottom paint in an area about two inches wide. A few months ago, when I removed the cockpit deck panel to access the radial drive wheel in order to see if I could attach a rudder position sensor, I noticed if I stepped on the radial drive, my weight would cause the rudder to drop a half inch, and then it would pop back up after I took my foot off it. Apparantly our rudder can move verically about a half inch, and its natural floatation is causing it float up and rub against the bottom of the hull. We don't notice any issue when we're under way, it doesn't seem to drag or anything when we turn the wheel. Anyway, is this a normal thing? Or is there something wrong with our bearings that needs to be addressed?

 

[Ed Schenck]

That's actually kind of a good thing. It means that your rudder is not yet saturated, it still floats. Did you study the design of the area around the radial wheel? Is it possible to place a collar and bearing surface anywhere to keep it down? My H37C has a shelf with a bearing on top and could easily accomodate one under the shelf. I have also seen boats with a nylon collar around the rudder stock at the top of the rudder. Not sure how you could make one without dropping the rudder. Even though you notice no steering problems I think I would fix that.

 

[robertsapp]

Ours has what I assume is the Foss foam rudder with composite rudder stock, and a fiberglass tube that's glassed to the hull (bottom) and deck (top) for the rudder stock to pass through. There's about an inch of rudder stock that sticks up through this tube, which has the radial drive wheel bolted to it. Nothing there that forms any kind of ledge that I could mount a collar below to hold the rudder down. From other reading, I believe I've seen that there should be an upper and lower UHMW poly bearing that the rudder stock passes through. I'm curious if there's any way these could have worn in a manner that would allow vertical movement, but little to no side-to-side play. You're right, this must definitely be a very dry rudder, because it feels like I have to put 20 or 30 pounds of pressure on it to make it drop, and it pops back up with such force that I imagine it would shoot several feet in the air if there wasn't a boat holding it down!

 

[Alan]

My rudder has two white poly bearings between the hull and the rudder. If your rudder is making contact with part of the hull I would check the radial play on the shaft. Try forcing the rudder side to side and note how much movement there is. A large amount could allow the upper surface of the rudder to contact the hull. Also verify that there are at least one and prefereably two poly bearings between the top surface of the rudder and the hull. There needs to be some kind of bearing material between the buoyant rudder's upward force and the hull.

 

[Alex Dare]

rudder

I think that's fairly normal on those boats. Like someone said, means you have a dry rudder. If it bugs you, it wouldn't be hard to make up a spacer around the rudder shaft to fit between the hull and the rudder blade. You'd need to drop the rudder to install it so not sure it'd be worth the effort. If it ain't broke....

 

[Brian M H23]

A 2-piece shaft collar should work very well for this problem
http://www.mcmaster.com/#catalog/116/1154/=92qnnh

Possibly doable on a nice day but could be a little tricky in the water!

 

[Don12364]

My H376 had a similar problem. I cut a short spacer (about 1/2" long from memory), from a piece of plastic sewer pipe of 1/4" wall thickness. Even though the diameter was a little larger than needed. I then cut a piece out of its circumference to suit the rudder stock which is 6" dia.
Then I sprang it onto the stock without removing the rudder.
It was then only necessary to secure it with a large stainless jubilee clip.
All that was some 8 years ago. It is still there, untouched, and still doing its job.

 

[John T1594]

I had the same situation on my 1980 H30 and I made my own friction gaskets. I cut two circles (O.D. 4.25") of #2 white plastic from the lids of a plastic spackle bucket and then cut a 2.5" donut hole in the center of each one. I made a radial cut across each circle and was able to spread and snap them onto the rudder shaft above the rudder (when the boat was out of the water). I shot some waterproof grease in between every year and they were still in place when I sold the boat after eight years.