Mike said: tried removing with the Park press but the threads just wanna fold over. i straightened the pin back up and hit with wd-40, now what?
Tools: 1/4 inch drift punch (pretty big), two pound hammer, 10 to 12 inch length of 2-inch diameter thick walled pipe, short piece of 2x4 or 2x6 wood and Vise-grips.
1. Use the punch and light blows from hammer to knock off threaded portion of cotter. The stub should now be a few mm's inside the hole in the crank.
2. With a helper or two, prop the bike up so that the crank is resting on one of the pipe and the other is on the wood on a solid floor.
3. Make sure the cranks are exactly opposite each other.
4. Hold the punch in the Vise-Grips, put the business end of it on the stump of the cotter, then apply the hammer to the hammer end of the punch. Cotter should pop out with a single hard blow.
5. If the cotter does not pop out on the first or second blow, make sure that the cranks are lined up, and rock the crank with the cotter that needs to come out so that the flat of the cotter is on the flat of the crank spindle (when a cotter is ridden loose for a while it gets a ridge on the taper toward the threaded end that keeps it from popping out.
6. Hit it again, harder. It will come out. With the crank propped up by a solid pipe, there is nowhere else for that force to go except to take the cotter out of the crank.
If you have a repair stand with a rotating head, you can use a longer pipe. Rotate the bike so that the pipe is supported by solid floor at one end, and the other end supports the crank at the cotter. I have NEVER failed to remove a cotter using this method.
Earle Young Madison, Wisconsin "I love brute force precisely applied."