DG news letter, Winter maintenance
If you don't specifically ask, the inspector doing the annual will
probably not do a complete lubrication of all bearings. It really
doesn't matter if a particular bearing is lubricated only every other or
even third year but if a control system doesn't get greased for 15 years,
you shouldn't be puzzled when it becomes stiff or even freezes up.

Translation David Noyes, Ohio

My LS1-F was turned up side down to inspect the bearings that are in the
elevator control system at the base of verticle fin. These are not exposed
without removing the skid and boaring a small inspection hole in the bottom
of the fuselage. While these bearings are free from the elements and
seemed to be in good shape they were dry. I am sure they had not been
lubricated since the ship was new 1975. Way longer than the 15 year period
mentioned above. Lubrication was definitely needed!
I recommend that all older Club Class gliders have these bearings
inspected at the next annual. Thanks, 5U