Automotive Technology

Information on Steering and Suspension Systems for Automotive or the Front End Assembly

A vehicle's steering system is a vital part of a vehicle's ability to move. The main functions of the steering system is to provide vehicle turning per will of the driver, directional stability, it converts the rotary movement of the steering wheel into an angular turn of front wheels, and absorbs road shock from being transmitted to a driver's hands.

A motor vehicle's steering system contains the following basic parts:

Steering wheel, Steering shaft and Column, Tie rods, rack, idler arms, Pitman arm, and drag or center link.

A power steering system contains addition components such as a power steering pump, steering yoke/damper, steering coupler, and power steering hoses

There are several different types of steering systems that are used in vehicles both modern and classic:

Rack and pinion: 

Most cars, small trucks, and SUVs use this type of steering system.  A rack-and-pinion gear set is surrounded by a metal tube, with each end of the rack protruding out from each end of the tube. A tie rod, connects to each end of the rack. The pinion gear is affixed to the steering shaft. When the steering wheel is turned, the gear spins, moving the rack. The tie rod at each end of the rack connects to the steering arm which is attached to the spindle. There are two types of rack-and-pinion systems:

End take off, where the tie rods exit from the end of the steering rack via inner axial joints

Centre take off, where the tie rod ends attach to the centre of the rack with bolts

Recirculating ball: Commonly used in heavy vehicles, trucks and the larger/heavier SUVs. The steering wheel is secured to the steering shaft which has a threaded rod at the end, like a bolt. When the steering wheel is rotated, it turns the rod. Therefore, when it spins, it moves the block. The block has gear teeth cut into the outside of it. These engage a gear that moves the pitman arm. The threads in the rod are filled with ball bearings which recirculate through the gear as it turns.

worm and sector: the steering shaft has a worm gear attached to it at its end. It meshes directly with a sector gear. When you turn the steering wheel, the steering shaft turns the worm gear. The sector gear rotates around its axis as its teeth move along the worm gear and moves the Pitman arm.

 Every car, truck, and utility vehicle has a suspension system that helps support the vehicle, absorb shock and bumps, and allows the vehicle to turn. The suspension is comprised of the following basic components:

• Wheels and tires
• Springs

• Shock absorbers and struts

• Linkages

• Bushings, bearings, and joints

• The steering system

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