Lower Rudder Bushing Removal?

[Dan Hill]

A little background on the reason and arrival to my question.

We are in our 2nd year of ownership of a 1988 28.5 hunter. Since the purchase I have been dealing with a seawater leak ONLY when under power. Items checked OK have been prop shaft seal (PSS), keel joint, through hulls, cockpit drain scuppers and engine cooling/exhaust system entire. The water comes in just aft of the prop shaft log and collects in the engine sump area, approximately 1/2-1 gallon an hour depending on boat speed. Absolutely dry when docked or sailing.

Through process of elimination I have determined the leak to be coming from the rudder tube somewhere just above her static water line. Under power, like most boats, she squats into the water causing this leak to start. Due to the design of this boat it is impossible to see the tube from the inside without major surgery to the aft cabin rear bulkhead.

I have searched and read every article and photo I can find on this set-up without much success. Warren Milbergs article about his vessel CrewZen is similar as far as the top rudder bushings but his lower bushing/bearing is different.

I removed my rudder and this is what I found.

The lower bushing is made from the same Delrin material as the upper bushings and it measures approximately 6" tall. It is my suspicion that the leak is migrating around this lower bushing and through a unseen crack or opening within the tube behind the pocket the bushing sits in.

As you can see in the pictures the bushing seams to be held up in place with a fiberglass plate of sorts. This plate measures about 1/4" thick and I'm sure the hull is thicker than this plate. I can insert a feeler gauge in between the plate and bushing almost an inch. I feel no screws with the feeler gauge while probing.

Has anyone seen this setup on your vessel and can shed some light?

Thanks in advance to all who respond!

 

[Warren Milberg]

Rudder bearings

When I replaced the upper bearings on My rudder, I also found no evidence of any kind of lower bearing. I designed one that was then custom fabricated by a local plastics shop. Of even more concern was the crack I found around the lower edges of the rudder tube. I think this crack was caused by the lack of support where the rudder shaft enters the tube. This was easy to repair,but would have been impossible to find without removing the rudder. Left undetected it could have sunk the boat....

 

[Dan Hill]

That's just the thing Warren, I do have a lower bushing in mine and it looks quite substantial. I just need to remove it so I can attempt a repair of the leak from the interior of the tube.

 

[kloudie1]

Interesting one, Dan. If the bushing is not too loose on the shaft, I wouldn't change it.. The bearings are often glued in place with a special glue that bonds to the slick bearing plastic. My suspicion is that your leak is at the outer edge of that "support plate" , where it is recessed into the same area as the rudder bearing tube base.. I would think that taking that plate off would show where the leak is.. between the plate upper surface and the bearing and into the boat through a void in the bearing tube base-to-hull glasswork, at the outer edge of that plate. I have not seen an arrangement like that.. It would be tempting to try to work some 5200 into that space on the upper side of the plate, but because it is probably full of "sea stuff", there would be no way of knowing how good of a bond you'd have.. You could sand to uncover the outer edge then use a vibrator tool with a fine blade to very carefully cut the plate out and clean everything and epoxy or 5200 the hole to stop the leak before re-installing the plate..

 

[Steve Walsh]

This is probably no help, but I had the same problem with my Newport 28 and it turned out to be the packing needed replacing at the top of the rudder tube. Only leaked under power. Would it be possible to temporarily seal the rudder tube hole where it exits the hull, fill rudder tube with colored water to locate the leak? Good luck and keep us posted on how you solve and fix the problem.

 

[amcmahon]

I think Steve is right. The bushing is not designed to seal.. The water seal is just above the waterline at rest, but drops below under power. I have an '84 h27 and had the same problem until I replaced packing (actually packing was completely gone). Here is a pic of the h27 setup. note packing should be replaced with rudder shaft in place. Basically, the four bolts are removed and the top flange will slip up just enough to fit the packing. Don't remember packing size, but it is much larger than what you use on shaft packing.

 

[Dan Hill]

AMC and Steve, the 28.5s don't incorporate a seal at the top of the rudder tube. The upper opening is above the water line far enough to eliminate the need for a packing.

Kloudie, I'm thinking on the same line about cleaning that gap as best as I can and forcing some 4200 or 5200 in. I can also see a small interior area above the bushing that may be suspect and will get the same treatment.

Thanks folks for the replies!

 

[Alan]

Years ago I removed the rudder from my 34 (same basic setup as the 28.5) and drilled several holes in the shaft tube into which I injected West epoxy impregnated with carbon black powder. After thoroughly cleaning the rudder shaft and tube I applied multiple layers of mold release wax on the rudder shaft and installed it. Then injected the epoxy through the holes in the outer shaft and allowed the epoxy to setup. The resulting 'bearing' made of epoxy ended all play in the rudder shaft for the balance of the years I owned the boat. When I sold her there was still zero axial play on the shaft. It was a project but the resulting fix ended the problem for good.

 

[kloudie1]

Neat bearing, Alan ! I would caution anyone considering to make absolutely sure the stock is really round before doing this. I worked with a friend on a big Deerfoot whose rudderstock was about 3/16"out of round.. We didn't notice until the rudder locked up after the new install.. Lots of grinding and sanding and honing later, we got it to work.. just something to verify before doing a tight fit bearing.

 

[Don12364]

Kloudie,
Do you really mean 3/16" = 0.187". It would readily be spotted during initial build. Also no bearing is likely to be able to handle this out of round limit.
Merry? Christmas,
Don

 

[redteledrew]

Fixing rudder tube leak also!!!

Our hunter 28.5 was letting water in while underway (stern above water at dock). Found to have stress cracks at base of lower bushing area. Had to cut away the three bulkheads (soaked and rotted as well) to get access.

Bulkhead rot most likely during previous owner's scupper and exhaust hose leaks that looked to repeatedly fill aft bulkhead compartments based on stain marks. This may have weakened the bulkheads