Those #@$%^& rudder torque tubes. --

The rudder torque tubes are quality products. Recent improvements have added gussets to prevent failures. However, getting them to fit and rotate smoothly can be a problem.
The tubes fit together fine until you add the bushings. Then things start to bind. Check the tubes for straightness. Also use a rod on the inside of the outer tube to check for welding sags or bumps.
A long rat tail file can help smooth the internal bumps. Some builders have reported success with a wooden dowel wrapped with sandpaper.
One of my torque tubes was badly warped. I finally stripped the powder coating and heated the weldment with a torch to straighten it.
spend some time on the torque tubes to get them perfect. Any drag on the assembly will be worse when you load it up with foot pressures.
John Pitkin
Greenville,TX