It's tough to get any socket onto the axle nut unless the muffler is loose. When I first got my NT, I tried an experiment. With the rear axle
clean and lightly greased, I wanted to see how much drag was on the axle and I found none, so what I do now is hold the nut using a box end wrench and apply the socket and torque wrench to the bolt head end of the axle.
ps. my initial idea was to reverse the axle so the nut would be on the left side but 2-secs later realized that I couldn't remove the axle with the muffler installed!