I had some excessive friction on my control column torque tube that I couldn't get rid of by loosening the fit of the nylon bearing block. It turned out to be the mounting of the aluminum bearing box on the right hand side. The mounting tabs welded to the fuse tubes weren't all at the same level and when I torqued the mounting bolts down it put the bearing in a bind. The solution was to experiment with several washers of different thicknesses under the box to level it up.

Jim