I purchased a used set of 280's and one of them is seized up. I tried lubing it and working it back and forth but its still very tight. Any ideas?

Is it seized up at the hinge or the cylinder? I'm assuming you removed hyd hoses.

i had one like that....took a sawzall and cut the shaft into multiple parts and they came out easier....one section was stuck solid so i had to drill it out...the shaft is 1/2" stainless OD rod thats threaded on the ends...i went and just made a new one instead of buying one from merc.

Thats a great idea! Yes the cylinder is removed, I used some C clamps and clamped it to a top and can get it to move a little...

Thanks