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Wheel AlignmentWheel Alignment

R. BortignonR. Bortignon

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Wheel Alignment AnglesWheel Alignment Angles

• tire positioning angles are…tire positioning angles are… castercaster

cambercamber

toe in or toe outtoe in or toe out

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Caster AngleCaster Angle• caster is the angle created by the tilting of the steering knucklecaster is the angle created by the tilting of the steering knuckle

visualize line thru upper & lower ball joints or thru the strutvisualize line thru upper & lower ball joints or thru the strut• positive caster helps the vehicle travel in a straight linepositive caster helps the vehicle travel in a straight line• helps steering wheel return to center after making a turnhelps steering wheel return to center after making a turn• caster caster does notdoes not affect tire wear affect tire wear• caster is adjustable on many cars, but not allcaster is adjustable on many cars, but not all

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Camber AngleCamber Angle

• is the tilting of the top of the tire in or is the tilting of the top of the tire in or outout

• is used to offset road crown & increase is used to offset road crown & increase directional stabilitydirectional stability

• camber camber isis a tire wearing angle a tire wearing angle• camber is adjustable on most cars, but camber is adjustable on most cars, but

not allnot all• negative camber reduces tire slip when negative camber reduces tire slip when

corneringcornering

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ToeToe

• toe is the difference in width between the front side of the tires & toe is the difference in width between the front side of the tires & the back side the back side

• toe is used to minimize tire wear & increase directional stabilitytoe is used to minimize tire wear & increase directional stability

• toe toe isis a tire wearing angle a tire wearing angle

Adjusting Camber & Caster – shims or slotsAdjusting Camber & Caster – shims or slots• double wishbone suspensiondouble wishbone suspension

shims or slots are used to slide the control arm in or out…shims or slots are used to slide the control arm in or out…before removing control arm, note the number & position of any shims or mark before removing control arm, note the number & position of any shims or mark

slot-to-shaft location – this simplifies reassemblyslot-to-shaft location – this simplifies reassembly

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Adjusting Camber & Caster - EccentricsAdjusting Camber & Caster - Eccentrics• double wishbone suspension & strutsdouble wishbone suspension & struts

eccentrics are rotated to alter caster od camber…eccentrics are rotated to alter caster od camber…before removing components for repair, mark the position of eccentric – this before removing components for repair, mark the position of eccentric – this

simplifies reassemblysimplifies reassembly

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Toe In/Out AdjustmentToe In/Out Adjustment• tie rod end length changes the toe-in or toe-outtie rod end length changes the toe-in or toe-out

• care must be taken when replacingcare must be taken when replacing tie rod endstie rod ends MacPherson strutsMacPherson struts control armscontrol arms

that wheel alignment is re-established once components that wheel alignment is re-established once components have been reinstalled have been reinstalled

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• regardless of the vehicle, wheel alignment is performed to…regardless of the vehicle, wheel alignment is performed to… increase tire lifeincrease tire life improve handling by maximizing tire contact with roadimprove handling by maximizing tire contact with road minimize corrections needed while drivingminimize corrections needed while driving

qualified, knowledgeable technician with modern qualified, knowledgeable technician with modern equipment is essential for correct wheel alignmentequipment is essential for correct wheel alignment