Spent the most of the week replacing the rudder on my Mk 1.5. Probably one of the most difficult jobs I have done. Difficult only because of the location. It may have been easier if I removed the aft water tank, but I did not want to do that. I followed the diagram in the wiki. Steering cables loosened, quadrant through bolt removed. Then went to work on the 4 bolts holding the quadrant halves together. Upside down in the aft lazarette for almost 4 hours getting those bolts loose. The factory did not use anti seize on them so the were severely corroded. Finally got the rudder out and off to the machine shop. Drilling the new holes was complicated by the fact that the factory did not drill the original holes square to the shaft. They were slightly angled making drilling the new ones more difficult. Finally got it back and after a half day rain delay installation was much easier than removal, except for aggravating the bruise on my chest from the first day was rather painless.
I decided to replace the rudder because I thought it was failing internally. Under power, if I let go of the helm, the boat would immediately turn left. What I found when I finally got it out was the shaft was severely corroded to about half the thickness of the metal where the lower bearing rode. Inside rust was visible where the mild steel plate attached to the shaft, so I may have had some twisting of the rudder on the shaft.
If you have a MK1 or 1.5 it would be wise to drop your rudder the next time you are on the hard to inspect the shaft for corrosion. I would put a scissors jack to support the rudder. Only remove the top retaining bolt and lower the rudder enough to move the bearing out of the way to look at the shaft. Should take less than 20 minutes to drop and reinstall. You don't need to do anything with the quadrant to lower it enough to inspect.
Picture of the corroded shaft.
Rust visible where mild steel attaches to the stainless post
What it looks like with all the foam/fiberglass removed
New shaft is double walled and filled with expandable foam. I am working on modifying the emergency tiller to fit this smaller diameter shaft. Probably only applicable to MK 1 and 1.5 boats.
Where did you purchase your new rudder? I am confused...why doesn't the factory emergency tiller/rudder cap fit your new rudder post?
This is the emergency tiller cap that came off my MK 1. Replaced with the same but new.
What I was commenting on was he said his new rudder post diameter was smaller than his old one snd thus the cap didn't fit. I don't get it? How did the rudder stuffing box and bushing fit? I must be confused. Ken?
let me amend the emergency tiller post. Only applicable to MK 1.5 boats. On our boats we do not have a fancy cap on the top of the shaft. The emergency tiller slides into the shaft and engages the bolt that holds the rudder retaining sleeve in place. I'll try to get a picture later.
Guys : First of all the boats with a "walk thru" transom have a different emergency tiller connection than the standard transom boats with the pictured E-tiller cap.
I wrote a number of Mainsheet tech note articles recommending that the MKI boats should drop the rudder down a bit (while on land) to inspect and reseal the rudder column.
With the rudder down a few inches - tape up the nylon bushing to the hull, gouge out the area where the stainless column enters the rudder layup, reseal that gouge with 3M5200, drop the bushing and raise the rudder back up in place.
This procedure as well a adding some "Gluvit epoxy" to the inside of the stainless column is also in WiKi will seal the rudder from leaking into the layup and internal ferrous "spade"
A few thoughts
In the first picture, the screwdriver represents the bolt that holds the rudder in the boat at the top of the shaft. I did not bring the entire kit home, there is a finished pipe in place of the PVC at the top that is the tiller. The second picture shows how the emergency tiller pipe engages the shaft. Too cold to paint today, the emergency tiller will get a good coat of paint before it returns to the boat.
Thanks Ron for mentioning the inspection. I followed your advice when we first bought the boat, saw no damage. Totally forgot about the inspection.
We picked it up from the factory because we were going to be in Fla on vacation anyway. The cost without shipping was about $2600. Unless they have a spare laying around, takes 3-4 weeks to get it made.
Ken were you able to confirm that you did or did not have the rudder moving independently of the wheel?
Except for the corrosion into the shaft was there anything else wrong with the rudder blade structure?
I saw a factory print for what is supposed to be inside my rudder and it looks nothing like what you have there.
I'm in for this replacement sooner than later with my boat as well. Not looking forward to it...
Dan, hard question to answer. Looking at the structure it looked to be solid. But over the last 3 or 4 seasons the boat was developing a strong pull to the left. Especially under power. Last season the autopilot was having a hard time keeping the boat on heading. Something was going on down there.