So I have a few Flashforge/PowerSpec/Monoprice dual extruder printers. My z axis nut stripped out and ordered an entire z axis assembly..so the above steps will greatly help swapping it out. A day later another one of my printers z axis nuts stripped out. Now bare in mind that my printers run for upwords of 18-20 hours a day...every day. So they are work horses for me. Now I have 2 questions:

#1 Where can I purchase just the z axis nut from US?
#2 Other than using lithium grease on all the rails...how do I stop the damn squeaking and going from home bed position to ready to print position? As lithium grease has not proved to do anything for me and imagine 11 printers making such sounds LOL...not too pleasant.

Much thanks!!!