What is the car rack?

The steering wheel is connected to a shaft that goes out of the passenger compartment and into the engine compartment. At the end of that shaft there is a gear that is called a pinion gear. The pinion gear meshes with the steering rack [gear] that runs left and right on bottom of car behind engine. The rack is responsible for pushing tires left & right (via other parts that connect rack to wheels) as you turn steering wheel.