I'm not sure this is always just normal. mine did this a little tiny bit when I got it.... used 8k miles on a dba trans.
The full lock grinding noise is normal on AWD cars.
over next 1500 miles it got worse and worse to the point it made noise even with small amt of steering wheel turn.
all along it was the trans... oil pump gear was walking off into 1st gear... chewed each other up and all other gears got worn from all the debris. Minor circlip failure like this can ruin the guts of your trans over time.
8 get it know what yur saying about the steering lock to lock --- most cars will make at least some excess noise at full lock.... so differentiating the sound could fool you into dismissing a real problem coming down the pike. Not trying to scare anyone but just sharing my experience with it. Seller told me it was all good and normal and Regal Nissan in GA had just given it a clean bill of health!
1500miles later Shep diagnosed the issue by watching a single video and listening to the noise. Once cracked open, he was spot on with the issue.
Do this to differentiate.... stand outside the vehicle at the back and put your ears to one of the rear wheel wells... and have someone else turn it lock-to-lock.
If ANY squealing/grinding is heard from the rear of vehicle... its your trans. Not a normal labored power steering noise which should eminate from front of vehicle.
For what its worth the noise I heard ALWAYS sounded like coming from front of vehicle while in drivers seat.
Soon as I got out to rear wheel well and had someone else turn the wheel it was completely obviously coming from the trans which for anyone who might not know is in the mid-rear of car connected directly to rear diff and runs a drive shift forward to front of veh.