I've had this 17-35, f/2.8 for 11 years now.   About 10 years ago, I sent it back to Nikon, under warranty, to have the squeaking AFS motor replaced.  That's not too uncommon, really, and the 17-35 has somewhat of a reputation for the AFS motor failing. But since that repair, it's been perfect, and maybe my most used lens.   But it's squeaking again.

It still focuses OK for now, but I may ship it off for repair anyway.  And after 10 years, I'm sure it could use a  cleaning.