Has the aircraft been washed with a pressure washer at any time that's always good for taking all the lubricant out of any bearing.
A friend of my brothers bought an aircraft that had been used by the Dutch police as a traffic spotter. He was told that the aircraft was maintained at one of the best facilities in Holland, money no object all that sort of thing.
The gentleman concerned was a bit of a perfectionist and he decided that the control action was not all it could be. Fortunately he had a friend who was a LAE so they set too putting things to rights. While they were at it they found a pair of pliers and two spanners in the control runs and two of the tufnol aileron cable pulleys were seized solid. In fact they'd been seized long enough for the cable to saw it's way down through the pulley to the steel sleeve that the fixing bolt went through.
