Steering rack

The steering rack is used to convert the steering wheel's rotational motion into a linear motion to change the direction of the wheels. The steering rack uses a rack and pinion gear set to convert the rotational motion it also uses a specific gear ratio to make it easier to turn the steering wheel. The rack also has a piston attached to it with fluid port on both sides of it on the cylinder surrounding the piston. The steering rack has a rotary valve where the steering column connects to the rack, the rotary valve opens and allows high pressure fluid to go to the steering rack piston. The fluid pushes against the piston when the steering wheel is turned to assist the driver when the vehicle is travelling at low speeds.

When servicing a steering rack it is important to fit the rack new seals when assembling it, to prevent the power steering fluid from leaking and to prevent dust and dirt from getting into the moving parts as it will wear it out faster. It is also important to check the play/clearance on the tie rod to rack connection and in the tie rod end ball joints. If there is too much play it may affect the vehicles toe and the vehicle's steering. The vehicle's play on the steering is caused by the clearance between the rack and pinion gears. The play between the gears is adjusted by a bolt that is connected to a nylon yoke, if the bolt is tightened the yoke pushes the rack closer to the pinion gear and when it is loosened the clearance is increased.

 Checking the run out on the rack gear