Grinding sensation when turning my 2001 Xterra to the left

Check drive shafts.

Count your blessings and keep your fingers crossed.

it the wheel bearing i bet you can feel it in the steering wheel when you turn

probably warped rotors caused by a mechanic who was to lazy to use a torque wrench when he installed them

Hi, grinding noise when you driving you should check the condition of your brake pads.

Brake pads and/or wheel bearings.
Fix them NOW or it's going to cost you 10 times more later

Noises can be tough...especially over the internet where the noise cannot be heard....WHERE are you hearing the noise? Does it sound like it is INSIDE the passenger compartment or OUTSIDE, like in the engine compartment"?

check your cv joint attached to the knuckle arm it must have been broken...

If you're talking turned full lock, sounds like your CV joints. I have had my 2001 in twice for this (damn it).
Have a look along the steering rack (near the axle) for your boot seals (probably a concertina style rubber cone about the size of your palm) for any signs of grease escaping through a split in the rubber. From underneath would be best, as the inner boots are a bit hard to see from above. I'm no pro, but this combined with the grinding is a dead giveaway in my experience. The joints have lost their grease and are now worn down. Look for new after market joints online then take them in and pay for the service. A full set plus service from a garage could set you back ~$800 otherwise.

sounds like the power sterring pump check valve is failing because it only when you turn, try to turn the wheels standing still to verify the noise, if noise present, replace the ps pump.