Depending on the what type of car or truck could be the brakes or rotors low brake fluid, or the boot is open and its gone dry, wheel bearings. hope this helps
countershaft bearing could be problem
Wheel bearing
I'd try changing tires, worked for me.
Throw-out bearing................
The grinding is a worn CV joint. Get it replaced before it causes more damage! A worn wheel bearing will make the same noise answer worn wheel bearings or worn brake pads will be the cause
Warped rotor and worn out brake pads.
The grinding noise you hear are your shocks and struts. If you experience bouncy while you are driving, as well, you should have them changed.
Could be a bearing going bad.
sounds like you need new brakes
it may be the drive shaft u-joints if its rear wheel drive
It depends on where the grinding noise is coming from. Most of the time the grinding is coming from the brakes and the brake pads need to be replaced. If they've been grinding for a while, the rotors will need to be resurfaced or replaced. Other possibilities for grinding are worn axle bearings, or a problem with the clutch. If the clutch goes out, there will be a grinding noise when you try to shift gears.
tie rods