I have been trying to remove the tiller from the rudder stock for a few days now, but bimetal corrosion has been fighting against me. I need to get it off do that I can repair the lower pintle and assess if the tube needs replacing.
I eventually won the battle with plenty of brute force and ignorance. The tiller is attached to the rudder stock by the above home made aliminium clamp bracket. The six holes that you can see contained socket head stainless steel bolts with the head fitting fairly snugly below the face of the block.
Over the course of several evenings I tried allen keys, then an impact driver. I then drilled through the heads with a 5mm drill, it still wouldn't release. I finally drilled the heads off with a 10mm drill and guess what... it still wouldn't release. I eventually had to get brutal with a Dagenham torque wrench and a wood chisel. I was worried that I would be causing greater damage with this approach but couldn't think of any way around it. After copious amounts of wd40 and about an hour of slogging at it it opened up enough to slide off.
The rudder and stock slipped through the hull only to stop short on my lawn. I tried to tilt the trailer forward on the jockey wheel but there wasn't enough clearance under my storm porch, it's a tight fit on my garden I can tell you... You wouldn't want to run out of the house too quickly, you'd knock yourself out on the transom :D
In the end I held the rudder up out of the way on a rope and dug down about 8", it was enough to let the end of the stock drop clear of the tube and let me remove the rudder.Under the tiller was this tufnol block with a brass or bronze bearing inside it. The screws had been knocked out of the GRP by my attempts to remove the tiller but there is no serious damage. There is also a similar set up at the bottom of the tube.
Under the collar was a sight to gladden the heart, it looks like the original galvanised steel tube has been replaced with a plastic tube. You can just see the end of if flush with the GRP. I just need to go and see my fabricator and get something made up for the lower pintle, then it can go back together.