A steering gear box is a device that transfers the rotational motion of your steering wheel to the lateral, side-to-side movement needed to turn your front wheels.
Steering gears fall into two general categories, a gearbox or a rack and pinion assembly. Each type of steering gear produces the same result, to turn the wheels to the right or left when you rotate the steering wheel. But they do their jobs in a slightly different way and with slightly different components.
Inside the gearbox is a set of gears and bearings that allow the driver, usually with help from power hydraulic assist, to easily turn the steering wheel in order to turn the wheels on the ground. The end of the steering column or shaft is connected to the input shaft on the gearbox. The output shaft of the gearbox connects to an arm that swings like a pendulum when you turn the wheel. This “pitman arm” translates the rotational movement of the gearbox into lateral movement through a set of rods or links to the steering knuckles and wheels.
This type of steering gear arrangement can be found on most vintage vehicles. Because of the mechanical advantage provided by a gear box over rack and pinion, it is also featured on many modern heavy duty trucks and SUVs.
To replace a steering gear box, a technician will first need to raise and support your vehicle in the air for access. The gearbox is located near the end of the steering shaft that connects to the steering wheel. Depending on your vehicle make and model, a number of other components might need to be removed in order to gain access to the gearbox.
In general, steps to replace a steering gear box include: