^As with any repair of a precision instrument, I don’t recommend
doing this yourself. I somehow managed to get lucky and was able
diagnose the problem with my lens and repair it, with the
auto-focusing, manual focusing, manual zoom and auto exposure all
If you don’t feel confident doing this repair yourself, I recommend you send your lens to a Nikon Repair facility. Remember,
if you are unable to repair it yourself, you will have a paperweight, a
lens that might not autofocus or at least a more costly repair if you
send it to Nikon.
That said, I started at the rear of the lens and removed the screws
holding the bayonet mount to the lens. The fact that there are a row of
electrical contacts made me think that it was likely that the patient
wouldn’t survive the surgery.
Under the bayonet ring there was a circular printed circuit board
with various flex connectors encircling it. I pried all of the
connectors free and unscrewed the rear element.
I eventually stripped the lens to the point where I could see the
zoom mechanism and how one of the three screws mounted every 120
degrees around the body of the lens was loose. The nylon foot that it
screwed into was now rattling around inside the lens. When it dropped
out, I inserted it back into it’s groove and used nail polish on the
screw threads to hopefully keep it from vibrating loose again. The lens
was assembled with some sort of thread locker on the screw but it still
managed to vibrate loose.
As they say in the auto shop manuals, reassembly is the reverse of
disassembly. The first time I put it back together, the zoom worked
fine, but the camera didn’t auto-focus. After taking the lens apart
again, I saw that the focusing prong was connected to the drive
mechanism. Another hour later, it was working.
Remember, don’t try this at home.