Ditto on the heat, but in that location, you'll need a lot of it! The cast iron pivot will bleed heat away about as quick as it's applied, so use an acetyline torch, and really warm it up. Just be sure there's no accumulation of grease, grass, or anything else flammable to catch fire while you're doing it, and watch out for hot grease squirting everywhere when it finaly lets go. I rehabbed a M-F tractor recently that had the spindles rusted into the front axle, so the steering wouldn't turn. That one took a rosebud torch and a lot of heating to break the rust loose.
Jerry
