Bpounds:
Excellent post. Makes sense what you are saying about where a bend would take place, and assures me I'm not dealing with that issue now. My jack legs look fine so I'm more certain my problem is with the UN-greased screw.
I like what you did with the drilling of holes, but right now think I'll start with the grease on the pipe insulation. My jack is in such a bind that the first thing I have to do is get the weight off it before I try anything.
After that, I'm hoping I can turn the screw shaft enough to work the grease up into the nut. If not, I'll drill and let the oil run down into the nut.
I'm feeling a lot better about this project and will tackle it in the next couple of days. Thanks for posting the pictures.