Extruder problems

I built a new extruder for my printer cause I had 2 printers sharing the same extruder lol. I had to swap it to each machine when I wanted to use it. The new one has a slight problem. The big gear tightens up and it stops moving after a few minutes. This is the standard greg's extruder. Anyone have any tips?

Double nut, make the inside one so that the extruder turns properly then tighten the second nut against it( holding the first nut in place).

I have a double nut on there. But i tightened it even more, it was only finger tight before. Will try again. Thanks