What do you call the part behind rotor on a 2003 mustang rotors. My was jack when dropped and bent. I need to replace it but know what is.?

The part behind the rotor on a 2003 Mustang rotor is called the hub assembly. It is a critical component of the vehicle's suspension system, as it connects the wheel to the axle and allows the wheel to rotate freely. The hub assembly also contains the wheel bearing, which reduces friction between the wheel and the axle and allows the wheel to turn smoothly.

If your hub assembly was damaged when your Mustang was jacked up and dropped, it is important to replace it as soon as possible to ensure the safety and performance of your vehicle. You can purchase a new hub assembly from a Ford dealership or auto parts store. The replacement process can be complex, so it is recommended to have it performed by a qualified mechanic.