How to remove a Seized Rudder bearing? Can you help?

smth448

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For my sins, I own a J-92. It uses self aligning bearings at the top and bottom of the rudder stock. The actual bearing is Nylon housed within an Alluminium housing. I have manged to remove the rudder complete with bottom bearing from the boat.
Any ideas on how to remove the bearing from the rudder? I have tried the big hammer and copious amounts of swearing!
 
Is it aligned straight?

Is it seated on an aluminium sheave on the rudder stock? could be the sheave that has corroded? Try pouring boiling water over the bearing and then lubricate?
 
The thing that makes it difficult is that the bearing has come out of the boat, complete with the aluminium housing. The housing rotates freely on the bearing but the nylon bearing has seized solid on the stock. The big stilson idea would work if we could get access to the nylon bearing, but it is enclosed in the housing.
In use this allows the rudder to move but not freely enough.
 
Your problem is that Nylon is indeed hydroscopic and swells when wet. Even the best grades swell a bit, so dry it out in a warm environment and try again. You will probably however not get it off without cutting it off as it has seized on the shaft and been rotating in the housing. This probably means the OD is worn too so frankly I would cut the damn thing off and get a new one made with a bit more clearance so it doesn't happen again.
 
Is it definatley Nylon? Torlon and Delrin and commonly used in the marine industry because they are less prone to water absorption!
 
First stop is the manufacturer to see if they have modified the design...and whats their preferred technique ?
As nylon swells with water,surely as it dries it will shrink more tightly onto the shaft?
I would be tempted to use heat but the danger is the heat transfering into the resin of the rudder via the s/steel stock before the nylon bearing has released . Nevertheless,heat/penetrating oil/a good tap with a drift(on opposing sides of the bearing end face),and a running water pipe to quickly cool the shaft if it gets too hot before you achieve movement...even if you damage the bearing beyond reuse,you are going to want to renew it anyway,aren't you?
 
I have managed to remove the bearing and also found the manufacturer, thanks to J UK.
The bearing itself is self aligning delrin held within an aluminium casting. This was held into the boat with sikaflex. The whole lot came out with a hefty and prolonged shove. I then lost some brownie points by letting the whole lot, rudder and bearing, dry out in the spare bedroom. After a week or so in there turned it upside down and a hefty whack with a hammer and the bearing slid off the stock.
The bearings themselves are made in France by JP3 Steering. www.jp3steering.com.
 
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