Good evening all! I own a 2014 Sierra Denali and unfortunately encountered the same seat movement. After reading some of the discussions I did have my dealer install the clips for my seat (the service advisor knew exactly what I needed and ordered the parts in advance). The fix did not work though. I made sure the clips were installed and noted the technician inspected for possible weld breaks also. I read in a discussion how an owner installed 2 clamps on the front rail to restrict the clips and thus the seat front shifting from side to side. I picked up a couple of clamps from my hardware store and installed them on the round tube the seat is attached to placing them snug against the outside of either clip. Worked! It's been over 2 months now without any shifting or noise of any sort. I've been a happy camper since.
I'm sure GM will come up with a more elegant solution, but in the meantime....
Cheers!
