My back right wheel makes a grinding/rubbing noise when i back up

Replace the right side wheel bearing. But before you replace it. Listen to see if the noise is coming from the front or back. If you can't tell, Put some one in the back seat. Front bearings usually make noise. rear bearings, the noise can come and go.

cv axle may need to be replaced

sounds like wheel bearing to me

sounds like you have a bad wheel bearing. the play in the bearing causes the brake rotor to rub on the caliper or the abs sensor rubs on the toner ring of the rotor.. check your wheel bearing.. hope this helps..

Check for a worn upper bearing plate/seat on the front struts.

it sounds like a wheel bearing also make sure the tire is not rubbing the fender wall to

I would investigate the transfer case. By your description here it sounds as if the gears inside are worn and the drive chain inside is rubbing, causing the loud noise you hear.

Wheel HUB bearing... find out which one (possibly both).

I had the same problem with my 2002 Mountaineer at about forty thousand miles. Murcury replaced the steering column free under warranty. I now have ninty two thousand miles and it's back. The rear end is making a whining noise, the tranny is starting to slip, and the rear window regulator went out. Why did we buy a Mercury?????? Disgusted Dave!!!

sounds like wheel bearings or 4wd might be stuck engaged... try cycling 4wd or checking grease packing first.