Bad wheel bearings if its from the tires. Jack it up and try to wiggle the tire. If it wiggles, theres your problem. If it's from the motor it's likely a fan shroud.
The rear of a Ford Explorer may have a grinding noise when driving, because the muffler may have came loose. The u joint may also be loose and cause a grinding noise.
wheel bearing?
The Grinding noise in the passenger rear of a 2002 Explorer is most likely either a bad wheel bearing, or a brake problem. Check the brakes then the bearing to find the cause.
The expedition door lock relay could be stuck causing the grinding noise. Check to insure that the lock relay is working properly.
I have a 1999 Ford Explorer and I was told about a grinding noise before I bought it. He told me that it was because it needs a new wheel baring. * If the vehicle is standing in place and the wheel is turned and there is a noise it could mean you need to add power steering fluid to the unit.
brakes or rear axle problems.
This is because of rabbits communicating.
Warped rotor and worn out brake pads.
The clutch assemble is shot...
it can be a couple of things such as hubs,driveshaft,u joints or fluid levels
Depnds on whats causing the noise. The most common grinding noise is from the brakes and fronts average $2-400.00 and rears about the same. This depends on year, make, model etc of the vehicle.
possibly brake pads worn down