I would also say it's the dust shield...BUT......
if it only happens when the wheel is turned hard right (all the way to the end) it is probably the right steering bump stop...it's a little plastic cap on the metal bump stop rod coming off the knuckle. The plastic cap can come off or wear through (my left one fell off and right one wore through), and then the metal end rubs against the lower control arm when turned to the lock.
I'll be willing to be that's your problem.
replacement bump stop cap: $1.75 from the dealer