Loose Focusing on Nikor 60mm

[HSakols]

Hi
I have my fathers old Nikor 60mm AF macro lens that he barely used at all. The lens looks brand new however, I notice that when I position the lens straight down the focus ring starts to move when at close distances.  Is there an easy fix to the problem?  Will Nikon fix it for less than it is worth? Personally I would like to fix the lens and sell it.  I much prefer my 105. 

Hugh

[Ellis Vener]

My recollection is that the older 60mm Micro-Nikkor design seemed to be worse in this regard than newer iterations.

[Colorado David]

I'm not anywhere near my lenses right now, but I have an older manual focus Micro Nikkor that has a knurled set-screw on the focus ring.  I'll have to look at it when I get back and post a clarification later.