Hi,

Chances are you won't see signs of wear on the screw thread it's self but you will feel any movement or Backlash and this is what your looking for.

I think your going to have to provide some good quality pictures of the problem area for us to help more.

I very much doubt they have built them not to be disassembled so chances are they are just securely bonded with some form of compound and fastening method.?

Post pics and lets see.!