Push tube question

[Brian Rauchfuss - PCD <brauchfu@pcocd2.intel.com>]

I am putting together my control system and I am wondering about the
small diameter push tubes used in the cockpit module for the ailerons.  
The end piece of each push tube is a ball with a hole drilled through
it for a bolt; the ball is allowed to rotate, but it rather stiff moving.
What part is the bearing?  The ball seems too stiff, but I doubt that 
the bolt is not to be tightened fully.

Brian