Mine was the same way, but considering it had been sitting in the field for 21 years, and was full of mouse turds, mud dauber nests, pecan shells,bird crap, and plenty of red Oklahoma farm dirt, the fact that it would move at all was amazing. I steamed it off at the house here when I started the rebuild, and after about a half can of good quality penetrating oil, and some gentle persuasion, and the other half can of oil, it now shifts smoother than runny baby dung going down a greased glass funnel. Ain't really much there to wear out, just needs some TLC. Good luck.
DJ