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Home , Camber angle, Caster angle

AUMT 1316 - Alignment 11/15/11

Steering and Suspension and Suspension

• Camber is the amount that the centerline of the wheel tilts away from true vertical when viewed from the front of the • Camber places the tread flat on the road Donald Jones reducing tire wear and improving vehicle Brookhaven College handling • Excessive camber will cause wear on the edge of the tire’s tread

Steering and Suspension Steering and Suspension Camber Split

• Camber split is the • Positive caster is the difference between the rearward tilt of the left and right camber steering axis settings • Negative caster is the • Excessive camber split forward tilt of the steering axis will cause a vehicle to pull to the most positive • The vehicle will pull to the least positive side side • Not a tire wear angle • Camber split should be limited to ½ a degree or • Caster aides in directional stability and steering less to prevent vehicle wheel return pull

Steering and Suspension Steering and Suspension Caster and Ride Height Angle

• It is important to • Inward or outward variation of from a consider normal straight ahead position vehicle loading • Toe in is referred to as when performing positive toe • Toe out is referred to as alignment checks negative toe and adjustments • Not a directional control angle • What effect does • Toe is a critical tire wear loading the truck angle that commonly have on caster? causes feathered tire tread wear

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Steering and Suspension Steering and Suspension SAI and Included Angle

• SAI - Steering Axis • Scrub radius is the Inclination distance between • Angle between the the tread centerline steering knuckle and the point where pivot points and a projection of the true vertical steering axis angle • Included Angle would contact the • Sum of SAI and road surface camber

Steering and Suspension Steering and Suspension Scrub Radius & Wheel Offset Toe Out On Turns

• Toe out on turns is the difference in turning angles between the two front tires measured at a specific turning angle • Customers concerns about toe out on turns are usually related to tire squeal during low speed parking maneuvers • Improper toe out on turns is commonly caused by bent or damaged steering linkage and/or steering knuckles

Steering and Suspension Steering and Suspension Thrust Angle Suspension System Service

• Thrust angle is the • Alignments are often considered part of routine difference between vehicle maintenance the centerline of • A vehicle’s alignment should the vehicle and the always be checked and adjusted after performing thrustline of the any steering or suspension rear system service that could impact alignment angles • Negative - rear • Proper wheel alignment point left affects vehicle handling, • Positive - rear control, ride quality and tire wheels point right life

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Steering and Suspension Steering and Suspension Alignment Pre-Checks Tire Inspection

• Tire pressure and • Check and adjust tire condition pressure to the vehicle manufacturer’s • Evidence of recent specifications collision damage • Inspect the tires for • Ride height abnormal wear such as • Wheel bearings • Center wear • Wear on both outer • Steering linkage edges • Suspension • Wear on one outer edge • Feathering components • Cupping or damage

Steering and Suspension Steering and Suspension

Bearing Adjustment Inspection Steering Linkage Inspection

• Wheel bearings • Steering linkage should should be inspected be inspected for for proper excessive wear or damage adjustment or • Attempt to rock the tire excessive wear from left to right • Attempt to rock the • Carefully inspect the tire from top to linkage for evidence of bottom damage

Steering and Suspension Steering and Suspension Suspension Inspection Types of Alignments

• Inspect all bushings for • Center line alignment evidence of damage, • The vehicle’s front wheels cracking and wear are aligned to the vehicle’s center line • Inspect control arms, springs, ball joints, etc. • Thrust angle alignment • The vehicle’s front wheels for evidence of damage are aligned to match the and wear rear wheel’s thrust angle • Inspect shock • Four wheel alignment absorbers and struts for • All four wheels are aligned leakage and damage to the vehicle’s center line

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Steering and Suspension Steering and Suspension Alignment Procedure Alignment Adjustments

• Perform alignment pre- • Compare the alignment checks specifications to the • Set up the alignment vehicle’s actual settings computer as per the and adjust in the equipment following order manufacturer’s instructions • Rear camber • Mount and compensate • Rear toe the alignment sensor • Front caster heads • Front camber • Measure caster • Front toe

Steering and Suspension Steering and Suspension

Camber and Caster Adjustment Control Arm Shims

• Camber is adjusted • Adding shims between the control arm and by moving the top of frame as shown moves the tire inward or the upper outward inward • Caster is adjusted • Changing the shim pack dimensions allows the by moving the upper technician to change steering pivot point caster and camber forward or backward • Some use shims to move the control arm outward

Steering and Suspension Steering and Suspension Moveable MacPherson Strut Adjustable Strut Rod

• Elongated strut • Change strut rod length mounting holes may moves the lower ball allow the strut to be joint to be shifted forward moved to change caster and/or camber and rearward • Some vehicles require • Moving the lower ball you to rotate the strut in joint forward increases mount holes to make caster changes in caster and/ or camber

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Steering and Suspension Steering and Suspension Control Arm Cams Toe Adjustment

• Eccentric cams allow • Toe is adjusted to the technician to move set the tires parallel the upper ball joint in to one another while and out the vehicle is • Moving both eccentrics equally changes only moving camber • Toe is adjusted by • Moving one cam in and increasing or the other cam out an decreasing tie rod equal amount changes length only caster

Steering and Suspension Toe Adjustment Procedure

• Set the steering wheel straight ahead and lock the wheel • Parallelogram • Loosen the clamps • Rotate the adjuster sleeve • Tighten the clamps • • Loosen the tie rod end lock nut • Rotate tie rod • Tighten tie rod end lock nut

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