Cotter pins in King Kutter blade nuts have me stymied

[Mudfarmer]

I have had a King Kutter Pro bush hog for about 8 years with new blades for it sitting in the shop for about three. I decided I needed to change out the blades this week. When I look down the access hole to the threaded top of each blade shaft I see a crown nut secured by a cotter pin. The cotter pin looks like it has been peened to the nut. There is no room through the hole to get to the cotter pin. I decided to try taking off the stump jumper plate from below to access the nuts easier. After struggling for about 10 minutes with the cotter pin holding that crown nut , I finally got it out. The nut came loose without difficulty, but I had no luck getting the plate to drop off once the nut was removed. (I was working from below with the mower on the three point and blocked up.) So I gave up.

What I would really like to do is get the cotter pins out of the nuts on the blade shafts and never put them back in. Any suggestions on either working from above to get the cotter pins out or for getting the plate off from the underside? By the way I have no electricity on my tree farm so take that into consideration. Sorry about no pictures, but if you have a solution for me you are obviously familiar with the type of machine.
MF

 

[zzvyb6]

In my experience, Cotter pins are soft steel and locking in place a castle nut, which is usually hardened steel. So if it doesn't pull out easily, I just wrench the castle nut and it shears the pin cleanly. Then a nailset can be used to remove the 2 pieces remaining in the bolt or axle.

 

[Alan W.]

zzvyb6 is right the cotter key will shear easily.
The center shaft has a taper on it so it only takes a little movement for it to fall loose.
I had to pull mine off from my Kingcutter to replace an oil seal.
Ive also got new blades and bolts to replace when I get a chance.
Do yourself and any future owners a favor and use anti seize during reassembly.

 

[Mudfarmer]

Thanks guys,

I managed to twist the cotter pin tails up and out of the way and file down the head in order to get my socket on the nuts. Low and behold I was able to break the nuts free with my breaker bar. Learn something everyday.