Hello, I hope the following assists you.
The Ranger has plastic lock stops for the steering, when the plastic wears through and the steering is on full lock it means there is metal to metal contact this is the grinding noise you hear.
The plastic lock stop covers are available as a separate part Ford finis(###) ###-#### you can see the lock stop near the track rod end in the image below, somebody has put grease on where the stop contacts to try to stop the noise.
Let me know if I can assist further and I'll reply as soon as I'm able to.
Thank you, I have checked and both lock stops are missing! Is the steering box adjustable?
you can't adjust the steering to stop these hitting, fit ne caps and lock stops if they are missing and this will cure the concern. The lock stops shouldn't need adjusting unless they have been disturbed or a wheel is fouling the arch on full lock.