The old warhorse AF-S Nikkor 28-70mm f/2.8 suffered an Impact injury about 8 yeas ago.
Since then it has been an ongoing project to repair it,,,
Today sucess
The cause was me kneeling down in just the wrong angle to empty the lens out of my Billingham West
First obvious thing was the Lens hood bayonet had cracked. So the spare came in hand
The focus ring had a small deep mar indicating point of impact as well this was to be repaired internally by dremel the bump away.
Still there was issues focusing and here I found the below two videos now and they give the answers to the rest of issues.
Faulty AF - Encoder pickup
https://nikongear.net/revival/index.php?topic=2193.0 and the internal flex board getting loose as well as details on wires etc.
https://www.youtube.com/watch?v=5SIsPnFG3pc&t=33sSo grateful
Make sure to see both videos first, will save you time in the end
As always