The black ring containing the meter coupling lever on my F3HP is just a tad slow to return to the desired position when I go from small to large apertures. It takes about a half second for the meter display to register the correct speed. No problem going from large to small apertures, and otherwise the camera does not need a CLA. But I can only imagine it will get worse over time. It appears to be a lubrication issue - and if I can somehow do this work myself, I would like to try it. Anyone have any suggestions? WD-40 a no no? Thanks!