Part of a rack-and-pinion steering system, the rack is a bar parallel to the front axle that moves left or right when the steering wheel is turned, aiming the front wheels in the correct direction.

Most car-based vehicles use rack-and-pinion steering in which the steering wheel turns a pinion gear that moves on a rack to turn the front wheels. Others use recirculating ball systems in which ...

That investigation into the electronic power steering rack and pinion assembly, electrical hardware and related electronic controls used in Model 3 and Y vehicles remains open, according to NHTSA.