I have a Nikon F4. The autofocus drive mechanism would not stay out after pushing in the lens release button. I took the lens mount off of the camera (4 screws). Everything looked fine and I replaced back on. After pushing the lens release in and out a lot of times it is now working as it should. The camera had not been used in a while. Everything appears to be working correctly. The autofocus focuses like it should. My question is: By taking off the lens mount, does anything get out of alignment? Does the autofocus have to be re- aligned? I did not think about an alignment issue untill after I had removed it.There are no adjustments that can be made to the mount.