Re: [J/4X-owners] Digest for j4x-owners-group@googlegroups.com - 3 updates in 1 topic

[Ed S]

Bill,

I can’t say for sure that it was due to the spacing between the flange shelf and upper bearing, but I did have a couple bolts tear out the shelf on which the bearing flange rests. The holes for those fasteners had been drilled precipitously close to the edge of that shelf. When I replaced that upper bearing, I did some epoxy work to resolve that and reduce the gap. 

A better solution is shown in the attached photo. I hope Jay P-A doesn’t mind my sharing a photo of his work here, as I intend to mimic it one of these days. 

I’d also like to point out that the rudder structure is much beefier on a J/42 than a 120. Our enormous rudder post passes through the hull above waterline, and there’s additional structure above waterline as well. It’s an incredibly beefy set up. Even so, taking a hit from a submerged object at speed, as Alliance did, would surely ruin your day. 

Ed

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On Apr 23, 2026, at 00:29, j4x-owne...@googlegroups.com wrote:



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• Upper Rudder Bearing Scantlings - 3 Updates

Upper Rudder Bearing Scantlings

Bill Bowers <wfb0...@gmail.com>: Apr 22 10:09AM -0700 [image: IMG_1076.jpeg]   I am overhauling the Whitlock Cobra Premier pedestal assembly on J42 #3 ConverJence to include new bearings, rose joints and strip/prime/powder coating the pedestal rectangular post.   Noting the USSailing Incident reports from 2024 NBR regarding upper rudder bearing issues with Alliance (sunk after upper bearing torn out of its mount) and Ceilidh (had to add 4 screws to prevent bearing shifting). These are both newer open transom J boats with upper bearings in the cockpoit sole very close to the lower bearing. The lessons learned included need to eliminate or avoid the common ~1/8” clearance between the hole in the composite and the outer wall of the upper bearing, thereby placing all the side loads on just the bolts thru the composite.   The photo shows that our bearing has that gap and is indeed just supported by the cured bedding compound and 8 throughbolts. The glass side wall of the bearing pocket is 1/4” thick.   The good news is the ghenerous 30’” spacing between the upper and lower bearings provides far more support than the open transom boats.   As the lower and upper bearings of the ruddser have no play and turn smoothly I am inclined to not drop, tear out, reinforce and rebed the upper bearings at this point.   Has anyone heard of problems with any after deck J4x upper bearings attributed to open space around the bearing?

Todd Stevens <todds...@me.com>: Apr 22 10:58AM -0700 Not exactly sure of the arrangement on a J/120, but I thought that the report on Alliance was strikingly similar to what happened to J/World in 2009. I don’t recall that they had time to examine the upper bearing, but it was thrashing around loose. I was under the impression that it was our kind of poop-deck arrangement because IIRC one of the first signs was that the engine panel was punched out into the footwell. But in both cases, I think the hull was ruptured too. Keeping the bearing in place might help stop the rudder from thrashing around, but IDK if it would have helped either of those boats stay afloat.   I have thought more than once about trying to wall that aft lazarette off from the rest of the boat.

<ankg...@gmail.com>: Apr 22 01:07PM -0500 ‘Wall off the aft compartment from the rest of the boat’: Yes! Why is it that we’re not doing that? Seems obvious, doesn’t it? There are a few details to work out:     1. How to run the engine exhaust 2. How to clear the steering cables 3. How to drain the compartment if there’s any water collecting from rain or the lower bearing.     Maybe we just install temporary barriers that we can put in place for blue water races such as NBR etc?     Al Goethe     From: 'Todd Stevens' via J/4X Owner's Group <j4x-owne...@googlegroups.com> Sent: Wednesday, April 22, 2026 12:58 PM To: j4x-owne...@googlegroups.com Subject: Re: [J/4X-owners] Upper Rudder Bearing Scantlings     Not exactly sure of the arrangement on a J/120, but I thought that the report on Alliance was strikingly similar to what happened to J/World in 2009. I don’t recall that they had time to examine the upper bearing, but it was thrashing around loose. I was under the impression that it was our kind of poop-deck arrangement because IIRC one of the first signs was that the engine panel was punched out into the footwell. But in both cases, I think the hull was ruptured too. Keeping the bearing in place might help stop the rudder from thrashing around, but IDK if it would have helped either of those boats stay afloat.     I have thought more than once about trying to wall that aft lazarette off from the rest of the boat.           On Apr 22, 2026, at 10:09, Bill Bowers <wfb0...@gmail.com <mailto:wfb01983@gmail.com> > wrote:     <IMG_1076.jpeg>     I am overhauling the Whitlock Cobra Premier pedestal assembly on J42 #3 ConverJence to include new bearings, rose joints and strip/prime/powder coating the pedestal rectangular post.     Noting the USSailing Incident reports from 2024 NBR regarding upper rudder bearing issues with Alliance (sunk after upper bearing torn out of its mount) and Ceilidh (had to add 4 screws to prevent bearing shifting). These are both newer open transom J boats with upper bearings in the cockpoit sole very close to the lower bearing. The lessons learned included need to eliminate or avoid the common ~1/8” clearance between the hole in the composite and the outer wall of the upper bearing, thereby placing all the side loads on just the bolts thru the composite.     The photo shows that our bearing has that gap and is indeed just supported by the cured bedding compound and 8 throughbolts. The glass side wall of the bearing pocket is 1/4” thick.     The good news is the ghenerous 30’” spacing between the upper and lower bearings provides far more support than the open transom boats.     As the lower and upper bearings of the ruddser have no play and turn smoothly I am inclined to not drop, tear out, reinforce and rebed the upper bearings at this point.     Has anyone heard of problems with any after deck J4x upper bearings attributed to open space around the bearing?     -- You received this message because you are subscribed to the Google Groups "J/4X Owner's Group" group. To unsubscribe from this group and stop receiving emails from it, send an email to j4x-owners-gro...@googlegroups.com <mailto:j4x-owners-group+unsubscribe@googlegroups.com> . To view this discussion visit https://groups.google.com/d/msgid/j4x-owners-group/8de874aa-0055-4376-b3fc-bf1ec9c3d97bn%40googlegroups.com <https://groups.google.com/d/msgid/j4x-owners-group/8de874aa-0055-4376-b3fc-bf1ec9c3d97bn%40googlegroups.com?utm_medium=email&utm_source=footer> . <IMG_1076.jpeg>     -- You received this message because you are subscribed to the Google Groups "J/4X Owner's Group" group. To unsubscribe from this group and stop receiving emails from it, send an email to j4x-owners-gro...@googlegroups.com <mailto:j4x-owners-group+unsubscribe@googlegroups.com> . To view this discussion visit https://groups.google.com/d/msgid/j4x-owners-group/997D47AF-47E0-4D74-8202-9ECC6722AF2D%40me.com <https://groups.google.com/d/msgid/j4x-owners-group/997D47AF-47E0-4D74-8202-9ECC6722AF2D%40me.com?utm_medium=email&utm_source=footer> .

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[Chris]

That looks like a great solution to strengthening the bearing mount. I am looking to do this on Spice this year or next for peace of mind, as I've heard that the top bearing is a weak point because of the fasteners being relied on, as has been commented. I replaced the bottom bearing and ran out of time for the top, and haven't gotten back to it - this looks like a great solution, and easily enough implemented, thanks for sharing it.

Regarding walling off the aft part of the boat, I've thought about that as well, and if I were to do it would leave a small drain at the low point to allow water to get to the bilge, and would leave a gap for the steering cables to get through, also. It would slow the entry of water enough that it would be reasonably easy to block the passages completely in an emergency, without making any of the systems too complicated (my opinion, obviously).

[Todd Stevens]

That’s reminiscent of the reinforcement plates needed to retrofit strut towers on late 90’s BMW Model 3’s. Different failure mode though: hit a good pothole and they’d punch out the top.  

On Apr 23, 2026, at 05:15, Ed S <esi...@gmail.com> wrote:

Bill,

I can’t say for sure that it was due to the spacing between the flange shelf and upper bearing, but I did have a couple bolts tear out the shelf on which the bearing flange rests. The holes for those fasteners had been drilled precipitously close to the edge of that shelf. When I replaced that upper bearing, I did some epoxy work to resolve that and reduce the gap. 

A better solution is shown in the attached photo. I hope Jay P-A doesn’t mind my sharing a photo of his work here, as I intend to mimic it one of these days. 

I’d also like to point out that the rudder structure is much beefier on a J/42 than a 120. Our enormous rudder post passes through the hull above waterline, and there’s additional structure above waterline as well. It’s an incredibly beefy set up. Even so, taking a hit from a submerged object at speed, as Alliance did, would surely ruin your day. 

Ed

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[David Jade]

Out of curiosity I took a look at our J/46. I wonder if this is stock or has someone already done the work to replace and strengthen it all. 

David                      _/)

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On Apr 23, 2026, at 10:45 AM, Chris <j44s...@gmail.com> wrote:

That looks like a great solution to strengthening the bearing mount. I am looking to do this on Spice this year or next for peace of mind, as I've heard that the top bearing is a weak point because of the fasteners being relied on, as has been commented. I replaced the bottom bearing and ran out of time for the top, and haven't gotten back to it - this looks like a great solution, and easily enough implemented, thanks for sharing it.

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[Tom Keffer]

I did something similar to Ed. Unfortunately, I did not take a "before" picture.

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[Chris]

That looks great also, Tom - did you make up the donut in a mold and glue it in place, or create it with a mold in place, or is it G-10 or some similar manufactured board that you cut and glued in?