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Discussion Starter #1
We finally got the rudder dropped yesterday from Compass Rose. As you may recall, I had a fair bit of lateral movement in the rudder, which I felt was due to failure of lower bearing. There are many documented cases of J/Boats whose oem Harken bearing have been replaced due to corrosion, etc. I've been researching options and trying to find out more information on the bearing installed in J/28; in the course, I spoke to J/Boats, Harken, TPI (Pearson), Waterline and a few others....no help at all.

More for the FYI of the other 70 J/28 hulls out there....this boat did not, repeat did not, have Harken bearings. Imagine my surprise (and a little dissapointed...not as sexy)....the 'bearing' is simply a stainless collar that turns in a delrin sleeve. There was zero grease remaining. I want to point out that the official "J" owners manual makes NO REFERENCE to the bearing system used or maintenance requirements for the bearings. So, owners...add this to your commission list.

From what I can tell, as we haven't put a micrometer on the surface to measure, the delrin surface has been worn, which is allowing the lateral movement. It's possibly out of round as I can feel some binding towards the ends of travel. There is some surface corrosion on stainless steel sleeve, but nothing that really concerns me at this point.

We have not come up with a solution, at this point.

I am thinking that the delrin sleeve needs to be replaced for sure. Probably will wait to see how the stainless sleeve cleans up. As much as I'd like to throw a roller bearing in there....I probably can't justify the $$$ for the part, plus the engineering costs.

Here are some of the pictures I took. You can visit for the entire library.Picasa Web Albums - Jason - Rudder_Bearing
 

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You generally do not grease delrin nylon bearings. They're not designed to be used with grease, and if you grease them, they will generally gum up with dirt and dust and wear much faster. They're supposed to be rinsed occasionally, but not greased at all.
 

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Discussion Starter #3
You generally do not grease delrin nylon bearings. They're not designed to be used with grease, and if you grease them, they will generally gum up with dirt and dust and wear much faster. They're supposed to be rinsed occasionally, but not greased at all.
Interesting point. Thanks. If you look at the pictures, you can see the 'holes' in the delrin piece, along with the 'channel' between the two. There is a zerk fitting on each hole. On other J's of similar vintage these holes are occupied by set screws.

The delin part in question here is exposed, as it is below the waterline and below the packing flange that maintains the seal. Would this have any impact whether it is a greasable part? I can't imagine why the zerk fittings would be installed if the builder did not intend the bearing to receive grease.

Either way...we need to figure out how to fix...that is the next step!
 

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What size is the bearing ?

The bar stock is usally 1",2",3",4",5" Dia ect

Finding tubing in the right size is hit and miss

And then there are a LOT of grades like glass filled
 

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Discussion Starter #5
What size is the bearing ?

The bar stock is usally 1",2",3",4",5" Dia ect

Finding tubing in the right size is hit and miss

And then there are a LOT of grades like glass filled
I don't have the exact measurements, yet. But, I'd estimate the ID of the Delrin bearing is 5" to 5.75". I would expect the OD of the stainless sleeve to be close to the ID of the bearing...agree?

Do you have a recommendation on the proper grade to use?

What does the J/24 use? Do you know?
 

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J24 uses a SS pins off the transome :)

I really have no idea BUT i make a LOT of bearings for mixers out of normal delrin and it does fine

I also make a lot of valves spools out it which turn inside SS valve bodys



 

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The grease fittings might have been used to provide additional lubrication and to help exclude water from the rudder fitting, which would reduce the risk of the stainless steel corroding.

However, if the previous owner didn't use the zerk fittings to fill the area with grease on a regular basis, it would probably be worse for the stainless steel, since it would not displace the water and trap it against the stainless, leading to increased corrosion of the stainless steel.

Without a better view of the top of the rudder stock, where the stainless steel piece is, which does appear to be fairly corroded, it is hard to say what caused the problem. The band of corrosion does appear to line up with the channel in the delrin though.
 

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Discussion Starter #8
However, if the previous owner didn't use the zerk fittings to fill the area with grease on a regular basis, it would probably be worse for the stainless steel, since it would not displace the water and trap it against the stainless, leading to increased corrosion of the stainless steel.
It is my belief that the PO did not maintain the grease (probably because he did not know to do it).

Without a better view of the top of the rudder stock, where the stainless steel piece is, which does appear to be fairly corroded, it is hard to say what caused the problem. The band of corrosion does appear to line up with the channel in the delrin though.
The best picture I have of the stock is here: Picasa Web Albums - Jason - Rudder_Bearing
and here:
Picasa Web Albums - Jason - Rudder_Bearing

There are 2 stainless sleeves on the rudderstock; I am dealing with the lower bearing and sleeve for now.

Thanks for the feedback. I think we can agree this was a maintenace failure. Any ideas to repair / replace?
 

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Do other J/28's have the zerk fittings? I'm guessing these were an after thought. It looks like you have a roller upper bearing, maybe a Harken on the post. The stainless sleeve you have on the post looks the same as the one that is used with lower roller bearings. Is it possible that the boat was built with a Harken lower bearing and that a previous owner wanted to to do a cheaper replacement and added the Delrin bearing and zerk fittings?

Paul L
 

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Discussion Starter #11 (Edited)
Do other J/28's have the zerk fittings? I'm guessing these were an after thought. It looks like you have a roller upper bearing, maybe a Harken on the post. The stainless sleeve you have on the post looks the same as the one that is used with lower roller bearings. Is it possible that the boat was built with a Harken lower bearing and that a previous owner wanted to to do a cheaper replacement and added the Delrin bearing and zerk fittings?

Paul L
Paul, good questions. I haven't been able to look at another 28 to confirm.

The upper bearing consists of a stainless steel sleeve bonded to the rudderpost; it rides inside of a bronze tube / top plate bolted to the deck. There is another Zerk on the top bearing tube. I'm sure it is not a roller bearing.

I have no way of telling for sure, but I think the condition of the lower bearing probably makes it original. Other J's of similar vintage have the same 'holes', but instead of Zerks, they are set screws. I think the size of my boat probably doesn't create the loads required for a roller bearing...hence the Delrin setup.

Jason
 

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Discussion Starter #12
If you google "harken rudder bearing'

Jefa, imported by PYI comes up a lot as making copys of them


J40 Rudder Bearings

Yes, Harken got out of the rudder bearing business in the early to mid-90s. The circulated around the industry the drawings / specs for the bearings. There is even a bearing cross-reference document for J/Boats - Harken. The J/28 is not one of the models listed on that doc - the smallest is the J/32.

I am pretty sure I could use a Jefa roller bearing for a replacement, but this is likey a higher cost $$ option. I haven't ruled it out 100%. If I was planning
to keep the boat another 20 years...then I would consider it more strongly.
 

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Jason,

Wow what a coinsidence. I'm pulling the rudder on my J28 tomorrow for the very same reason. I have hull #11 and sail in narragansett bay. I also have quite a bit of experiance making parts out of delron, it's very good stuff.

I'll keep up with you and let you know what I'm doing.

John

[email protected]
 

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Discussion Starter #14
Jason,

Wow what a coinsidence. I'm pulling the rudder on my J28 tomorrow for the very same reason. I have hull #11 and sail in narragansett bay. I also have quite a bit of experiance making parts out of delron, it's very good stuff.

I'll keep up with you and let you know what I'm doing.

John

[email protected]
John, sound good. Please post pictures for comparison if possible. Let us know how it goes.

Jason
 

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Well Jason, I wasn't as lucky as you. After removing the first two bolt of the quadrent I thought I was fat, dum and happy. The second two turned me in just fat and dum.
So far I've turned the two hex bolts into round bolts with an impact gun, I've cut the heads off with my dremal and tried screw drivers and wedges and it will not split on one side. I'll be cutting it off tonight.

I can tell you I don't have setscrews or zerk fitting in either the top or bottm bearings

John
 

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Hi Jason,

Well I did finally get the damn rudder out of the boat. I had to cut two of the bolts out of the quadrent and I still have got one of the bolts out of the holes.

Any way it's out. I havn't taken any pictures as my daughter took the camera to college with her. But with the execption of the color (mines red) it looks identical to yours. I have the same discolored areas and the same delron bearing. I havn't decided if I'm going to take the bearing out. Mine looks like it's glassed in and may just stay that way. I was surprised at how heavy the rudder is. I'm guessing 100+ lbs, is yours that heavy?

When your's came out did it slide out of the top sleeve or did you have to fight it like it did.

BTW, no grease fittings anywhere on my bearings.

Nice new J28 site hey?

John
 

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Discussion Starter #18
John, thanks for the update. It took 2 to handle the rudder as it came out so, yes, ~100lbs.

The delrin sleeve is definitely glassed or otherwise retained into the hull, either way the only method of getting it out will involve a big saw.

I pulled the bolt that retains the top stainless sleeve and serves as a rudder stop; it came out still attached to the shaft.

Given you have the same wear patterns on the Delin, I am questioning the value of the grease fittings, and grease in general. It's either to cushion the wear on the delrin, or displace seawater to mitigate the stainless corrosion, I suppose. Doesn't seem like it made a difference.

The leading idea (today) from the yard is to build up the derin sleeve with a carbon/graphite/epoxy fillet mix, then hone the surface back to oem tolerances. The only concern I have here is maintaining / creating proper bearing backlash.

If we decide to cut the old delrin out, then I have the option of replacing the delrin with the same material, or switching out to a roller bearing. These two solutions are pricy, I think.

Everyone else...feel free to chime in with comments.
 

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> I was surprised at how heavy the rudder is. I'm guessing 100+ lbs, is yours
>that heavy?
One thing worth doing while you have the rudder out is to put it on a saw horse with the bottom lower than the top and drill a couple of small holes near the lower end. See how much water comes out and for how long. A little is probably expected, alot is needs looking into. You can easily epoxy the holes latter.

Paul L
 

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Delrin is probably lower maintenance than roller bearings. The problem with using a graphite composite is that graphite can cause serious galvanic issues with aluminum, since it is more noble than the aluminum.
 
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