Wheel alignment


Wheel alignment

A wheel alignment is part of standard automobile maintenance that consists of adjusting the angles of the wheels so that they are set to the car maker's specification. The purpose of these adjustments is maximum tire life and vehicle-travel that is straight and true when driving along a straight and level road, although most machines and the technicians who use them set the alignment to adjust for crowned roads, as well as correct tracking when driving on turns.

There are 2 types of angles that should be adjusted regularly during the life of an automobile. The first type is called the Primary Angles and second type is called Secondary Angles.

Within Primary Angles, there are three adjustment parameters involved on each axle in order to properly align a vehicle. These adjustments are camber, caster and toe. It is important to note that on some cars, there may only be the ability to adjust for one or two of the parameters.

These three parameters can be further categorized into front and rear, so summarily the parameters are:
* Front: Caster (Left & Right)

* Front: Camber (Left & Right)

* Front: Toe (Left, Right & Total)

* Rear: Camber (Left & Right)

* Rear: Toe (Left, Right & Total)

* Rear: Thrust Angle

As for the Secondary Angles, the adjustment parameters are quite numerous. They are:
* SAI (Left & Right)

* Included Angle (Left & Right)

* Toe out on turns (Left & Right)

* Maximum Turns (Left & Right)

* Toe curve change (Left & Right)

* Track width difference

* Wheel base difference

* Front ride height (Left & Right)

* Rear ride height (Left & Right)

* Frame angle

Setback (Front & Rear)is often referred as a wheel alignment angle. However Setback simply exists because of the measuring system and does not have any specification from car manufacturers.
A camera unit (sometimes called a "head") is attached to a specially designed clamp which holds on to a wheel. There are usually four camera units in a wheel alignment system (A camera unit for each wheel). The camera units communicate their physical positioning with respect to other camera units to a central computer which calculates and displays how much the camber, toe and caster are misaligned.

See also

* Car handling
* Car maintenance
* Auto mechanic
* Tire rotation

External links

* [http://www.familycar.com/Alignment.htm A short course on alignment]
* [http://www.tiresizecalculator.info Tire / Wheel Size Calculator]
* [http://www.wheelsizecalculator.com Car database and calculator for Tire & Wheel Sizes]
* [http://www.alignyourtruck.com/news.html How Truck Alignments Affect Fuel Mileage]


Wikimedia Foundation. 2010.

Look at other dictionaries:

  • wheel alignment — See alignment four wheel alignment …   Dictionary of automotive terms

  • wheel alignment — noun : the alignment or adjustment of the front wheel suspension and steering mechanism of an automotive vehicle …   Useful english dictionary

  • wheel alignment gauge — A gauge used to measure the distance between the rims of the front wheels …   Dictionary of automotive terms

  • four wheel alignment — See four wheel alignment …   Dictionary of automotive terms

  • four-wheel alignment — In most rear drive vehicles only the front wheels need to have their wheels aligned because the rear wheels are on a fixed axle. However with front drive vehicles and rear drive vehicles with independent suspension, all four wheels need to be… …   Dictionary of automotive terms

  • Alignment — is the adjustment of an object in relation with other objects, or a static orientation of some object or set of objects in relation to others. * An alignment of megaliths: see stone row. * An alignment (archaeology) in archaeology is a secondary… …   Wikipedia

  • alignment — [1] When referring to wheel alignment, it is the proper adjustment of a vehicle s front or rear suspension for camber, toe in, toe out, kingpin inclination or steering axis inclination, and turning radius or toe out on turns, caster, and ride… …   Dictionary of automotive terms

  • wheel — A circular device, thin in relation to its face area, usually able to rotate about a central axle or pivot, with a durable but elastic rim or with regular teeth cut on the rim and for lightness often supported by spokes joined to the hub instead… …   Dictionary of automotive terms

  • alignment — a•lign•ment [[t]əˈlaɪn mənt[/t]] n. 1) an adjustment to a line; arrangement in a straight line 2) the line or lines so formed 3) mac the proper adjustment of the components of an electronic circuit, machine, etc., for coordinated functioning:… …   From formal English to slang

  • alignment gauge — See wheel alignment gauge …   Dictionary of automotive terms