Looks like both of you have the same problem I did. Does the popping noise only seem to happen on the drivers side? Can you sometimes feel it in the floor board. If you want to reproduce it, try this:
1) Get the wheel turned all the way to one side and the truck at a complete stop.
2) Slowly start moving and crank the wheel to the other side as your moving.
That's how I did it when I was showing my dealer. Also look at the drivers side lower control arm bolts and see if they look like they've been moving back and forth. You should be able to see when the washer has been scraping up against the arm frame mount.
Hope this helps you both. If you need anything else feel free to let me know.