I am rather new to the Cockshutt/Co-op world, but I have noticed the the steering shaft seems to like to rust/freeze solid in the cast iron housing up by the instruments. What is the best way to get the shaft loose again?
There should be a grease fitting on the housing. Right side about halfway down, I think. Of course, that doesn't mean it has been greased. I think there are bronze bushings in the housing so they shouldn't be rusted tight. Try some good penetrating oil (PB Blaster or Kroil) and give it time to work. Tap the end of the shaft and try to turn the wheel a tiny bit. You can also apply heat to the housing, on second thought, you're close to the gas filler so maybe not. Once you get it to move a little the penetrating oil should take care of it.
Mike, I've taken two seized shafts out of the Cockshutt 30/Coop E3 tractors and neither one had a bronze bushing. Not to say that none of them had it, it's just that neither of mine had the bushing. It took lots of heat to get the shaft to turn again. My advice would be to completely remove the shaft, clean up the inside of the housing and start over. The rest of your advice was spot on.