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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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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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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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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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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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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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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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Discussion Starter · #22 ·
John, good feedback, thanks again. I did not think of that.

I had (have) 1/2" of lateral play in the rudder, so I am facing a very worn delrin piece.

I think the biggest issue is the alignment when honed. If it is not PERFECT...it could possibly make the problem worse, or cause binding...which is why I am leaning towards a real roller bearing....maybe.
 

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Discussion Starter · #25 · (Edited)
J/28 Rudder Bearing Update

We've completed the overhaul of the rudder bearing on my J/28. This project certainly was a trial and error process, especially when it came to machining the new bushing.

As I explained in an earleir post, we found in the course of the removal that the bearing is in reality, a bushing, made of plastic/Delrin. The bushing is press fit into the hull and secured with set screws via the rudder tube. It did not appear to have any type of adhesive/sealant (5200, etc).

There is a 5" dia stainless collar affixed to the rudder shaft, which turns inside the bushing. My collar was slightly out of round. The yard deemed it serviceable and did not replace or machine the collar.

The new bushing material is a plastic called Vesconite. It shipped from Tennessee, so there is a US distributor. The bushing stock was machined to final demensions through a yard sub-contractor.

The first time the bushing was installed, the rudder would not easily go back into the hull. After 5 trips to the machine shop, each time taking off a couple more .002"....the rudder was aligned enough to be re-installed. It's important to point out that the rudder, old bushing and new bushing material were sent to the machine shop for the initial machine of the Vesconite bushing, but I don't know how or if measurements were made (this is my fault, I should have been more inquisitive...but I was trying to not piss off the yard folk).

J/boats uses a flax sealing system, that functions similarly to an over sized stuffing box. The yard used two layers of 1/2" packing to seal. I beleive the original was 3/8", but apparently the yard wasn't comfortable with the initial seal using 3/8".

The boat was launched Friday, and I have about 600 yards on the new bushing....moved from the yard to my slip. Overall, I think we chose the right materials, but the jury is still out on whether the stainless collar should have been replaced.

Of note, I am not happy with how much effort is required to turn the wheel. I don't have to manhandle it, but it doesn't spin as freely as before. The wheel pilot will turn the wheel (no load, done in the slip)...but to my ear, it is straining. Bottom line: it's 'pretty stiff'.

There are a couple possible issues: 1. The top sealing ring is torqued down too tightly on the (maybe) oversized flax packing, which is turn is creating too much friction against the stainless collar. 2. The tolerences between the Vesconite bushing and stainless collar are too narrow. 3. There is an alignment issue of the collar top to bottom within the bushing, creating friction.

I will report again after a proper sea trial under sail and power. The trip to the slip under power was short and I now know I have to get the engine aligned. While the rudder was out, I had the shaft and prop trued, then added a new split half coupling and a flex coupling (both by R&D marine / PYI) and a PSS shaft seal. I kinda knew it was going to need an alignment, but I was hoping it wasn't going to be as bad as it was.
 

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Discussion Starter · #30 ·
Hi Bill:

Welcome to the J/28 community. I have had absolutely zero problems with the bearing replacement since it was completed (now going on 2 seasons). The vesconite material is as-advertised and I am glad I used it. I would definitely recommend going with a FFP (firm fixed price) if you can get it, as I paid too much for the 'learning curve' by my yard.

The J/28 is the perfect boat for me, easily single-handed, fast for its size and comfortable below. This past off-season, I replaced all the standing rigging (something to check now that these boats are 20+ years old) - I had a cracked swage on the starboard lower. I pulled and painted the mast, re-wired the mast, etc. I actually re-rigged with rod instead of wire as the price delta wasn't much higher. Of note to all J/28 owners....I had a cracked spreader root bar - which could have been a disaster in the making. Had to have Hall make me a new one (they still have the templates). I pulled the chainplates to inspect and found some rotten core, which was removed and refilled with epoxy.

The only issues I've ever had with the Yanmar are: (i) a failed lift pump (ii) stripped bleed screw on the secondary fuel filter (iii) a bad injector - replaced both for ~$120. Other than that, she has been very reliable.

I never had the 'privilege' of the Martec on my boat. The PO replaced with a fixed 2-blade, which I have since replaced with a Variprofile 2-blade feathering prop. My experience with the martec is that they (i) aren't very efficient in fwd except in flat water (ii) don't go astern well at all. There are better options and improvements in prop technology since the martec was designed 20 yrs ago. I would recommend flex-o-fold or varifold.

No issue with the cutlass. And I've been satisfied (read no problems) with the rest of the drivetrain - which is to be expected since it is essentially new! (New Motor Mounts, New Split Shaft Coupling, Trued Shaft, New Prop, New Cutlass, New R&D Drivesaver plastic coupling).

As far as the engine not reaching rated RPM: Will the engine reach full RPM at the dock in neutral? And is the bottom clean? Fyi, the Yanmar tach is known for reading 'low'. I can get 3400 RPM on a clean bottom (but I don't like to run it there)

Bill, if you haven't already, please go over to Yahoo Groups and join the 'J28Sailors' group....

Happy to discuss further questions and, again, congrats on your ownership.
 

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Discussion Starter · #31 ·
Doug,

I'm here....just not not as active as before (I ran out of questions/problems to ask....lol).

How the new 37c treating you? My folks still have the 34c.

-Jason

Bill, where you from? Where do you sail. Always like to hear from jboat people. I sail on Kentucky Lake and there is a j/28 that sails here with us and is very competitive in our PHRF fleet. They are very nice good sailing boats. I have not seen Jason posting here lately so dont have your feelings hurt, but welcome to Sailnet!!
DD
 
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