your brakes are about to give out... you should go to wal-mart and have them replace them
Have your brakes checked, rust or wear on brakes can cause grinding when turning.
Brakes
The brake pads are worn out and need to be replaced. The grinding sound means your brakes are about to stop working.
Check your brakes(pads and rotors)
Bearings, cv shaft, or brakes.
The grinding sound means that the brake pads are worn down to metal and that sound you hear is metal to metal. you need to have the pads changed, the problem is that you will more than likely have to change the rotors also. The way to avoid this in the future is when you notice your brakes are making a squealing sound that means that the pads will need to be changed soon.
When motorcycle brakes lock, they make a light grinding sound accompanied by the loud screeching of the tires. When the brakes lock, the tires are forced to slide along the pavement until the brakes are released on the bike stops.
possibly your wheel bearing is on its way out
The Brakes inside of the wheel could be rusty in the back and cuz some Grinding sounds, or the Transmission is Wet and Rusty which can also make a Grinding sound, If it happens to your Car, Notify me at lil_carbon@hotmail.com, u need to tell me your car if u need help.... if u dont and its just a Random Question, dont add me lol but really, ill help
Check if muffler is loose, check if rear brakes are worn out & grinding
Worn out brakes.
It's hard to diagnose without hearing the noise, but if you're sure that it is not the brakes, it could be dirt/sand/rock in the brakes. If you're hearing the sound all the time (even when not applying the brakes), it could be wheel bearings.