steering systems

copyright 2011 - eric jaromin copyright 2011 - eric jaromin

Steering systems Steering systems

Parts and function Parts and function


Steering system Steering system componentscomponents

Steering wheel, column and shaft – driver Steering wheel, column and shaft – driver inputsinputs

Steering gear – changes direction – Steering gear – changes direction – rotating steering wheel into linear motionrotating steering wheel into linear motion

Steering linkage – connects steering gear Steering linkage – connects steering gear to steering armsto steering arms

Ball joints – allows movement of steering Ball joints – allows movement of steering components and suspensioncomponents and suspension


Steering Steering


Steering wheelSteering wheel

Attaches to steering column and shaft by Attaches to steering column and shaft by 1 or more fasteners, most single nut1 or more fasteners, most single nut

Have an interference fit on the shaft – Have an interference fit on the shaft – very tight fit, may need a pullervery tight fit, may need a puller

May contain an airbag assembly, radio May contain an airbag assembly, radio controls, cruise controls, etccontrols, cruise controls, etc


Steering wheel Steering wheel


Puller Puller


Steering columnSteering column

Contains and supports the steering shaftContains and supports the steering shaft May have a tilt mechanismMay have a tilt mechanism May have telescoping mechanismMay have telescoping mechanism Also houses ignition switchAlso houses ignition switch May be designed to collapse during front May be designed to collapse during front

impact – has plastic or soft metal rivets impact – has plastic or soft metal rivets that are easily damaged or broken from that are easily damaged or broken from improper use or removalimproper use or removal


Steering column Steering column


Steering columnSteering column


Steering column couplerSteering column coupler

Steering column couplers allow pivot Steering column couplers allow pivot points in the columnpoints in the column

Like a universal jointLike a universal joint Loose or worn couplers will result in a Loose or worn couplers will result in a

loose steering feel, vibration, noise, or loose steering feel, vibration, noise, or sticky steering feelsticky steering feel


Steering column couplerSteering column coupler


Impact Impact

If the vehicle is involved in a front impact, If the vehicle is involved in a front impact, always inspect the steering column and always inspect the steering column and wheelwheel

Squeaking, chirping or rubbing sounds Squeaking, chirping or rubbing sounds indicate damageindicate damage

Catching, binding and play indicate Catching, binding and play indicate damagedamage

Especially if the airbag deploys!Especially if the airbag deploys!


Steering ratioSteering ratio

Steering ratio is a measurement of how many turns of Steering ratio is a measurement of how many turns of the steering wheel it takes to go from a full lock to the the steering wheel it takes to go from a full lock to the other full lockother full lock

Basically how many turns from all the way left to all the Basically how many turns from all the way left to all the way rightway right

Also measured from the center (straight) to a full lock Also measured from the center (straight) to a full lock turnturn

Fast ratio is 3 turns lock to lockFast ratio is 3 turns lock to lock Slow is about 4 or 5 times lock to lockSlow is about 4 or 5 times lock to lock 15:1 ratio – wheels move 15deg for 1 deg of steering 15:1 ratio – wheels move 15deg for 1 deg of steering

wheel movementwheel movement


Variable ratio steering Variable ratio steering


Steering gear systemsSteering gear systems

Recirculating ballRecirculating ball Rack and pinionRack and pinion Power assistPower assist Electronic assistElectronic assist


Steering Steering


Recirculating ballRecirculating ball

Recirculating ball is used on trucks in Recirculating ball is used on trucks in modern vehiclesmodern vehicles

Used on most vehicles prior to 1980 and Used on most vehicles prior to 1980 and the use of front wheel drivethe use of front wheel drive

Uses balls on a worm gear Uses balls on a worm gear Has a pitman armHas a pitman arm


Recirculating ball Recirculating ball

Balls inside the gear ride inside guide Balls inside the gear ride inside guide pathspaths

Move from one end of the ball nut Move from one end of the ball nut through guides, back to the bottom of the through guides, back to the bottom of the housinghousing

Uses a Parallelogram Linkage steering Uses a Parallelogram Linkage steering arm systemarm system

Pitman arm moves steering tie rods Pitman arm moves steering tie rods


Recirculating ball Recirculating ball


Recirculating ballRecirculating ball


Rack and pinion steeringRack and pinion steering

Uses a rack and pinion gearUses a rack and pinion gear Pinion meshes with a gear on end of Pinion meshes with a gear on end of

steering shaftsteering shaft As gear rotates, pinion rotates and As gear rotates, pinion rotates and

moves rack left or rightmoves rack left or right


Rack and pinion Rack and pinion


Steering linkage Steering linkage

Steering linkage is anything connected to Steering linkage is anything connected to the wheels and the steering gearthe wheels and the steering gear

Tie rodsTie rods Steering armsSteering arms Steering knucklesSteering knuckles Ball jointsBall joints


Steering linkage Steering linkage


Tierods Tierods

Tierods are attached to pivot points on Tierods are attached to pivot points on each front wheeleach front wheel

The other end is attached to the steering The other end is attached to the steering gear or rackgear or rack

Allows for suspension movementAllows for suspension movement Used to adjust TOE of the car – tires face Used to adjust TOE of the car – tires face

in / \ or out \ / when driving straight in / \ or out \ / when driving straight


Tierods Tierods


Steering arms Steering arms

Tierods attach to the front wheels at the Tierods attach to the front wheels at the steering arms steering arms

The steering arm is attached to the The steering arm is attached to the steering knuckle, which includes the steering knuckle, which includes the spindlespindle

Used to get proper steering angle during Used to get proper steering angle during turns turns


Steering arms Steering arms


Steering knuckle and Steering knuckle and spindlespindle


Steering knuckle and Steering knuckle and spindle spindle


Ball joints Ball joints

Allow suspension movement up and Allow suspension movement up and down, as well as turning movementdown, as well as turning movement

Located in control arms – in lower, as Located in control arms – in lower, as well as upper control arm if so equippedwell as upper control arm if so equipped

Wear items – need replacement Wear items – need replacement periodically periodically


Ball joints Ball joints


Ball jointsBall joints


Steering designsSteering designs

Parallelogram – used on cars with Parallelogram – used on cars with recirculating ball gear steering recirculating ball gear steering

Rack and pinion – used on cars with a Rack and pinion – used on cars with a steering rack and pinion gearsteering rack and pinion gear


Parallelogram Parallelogram

Uses tierods connected to a center linkUses tierods connected to a center link Uses a pitman arm to move steering Uses a pitman arm to move steering

linkagelinkage Also uses an idler arm to support the Also uses an idler arm to support the

linkage on the passenger sidelinkage on the passenger side


Parallelogram steeringParallelogram steering


Pitman armPitman arm



Fewer moving parts than the recirculating Fewer moving parts than the recirculating ballball

Smaller and more compactSmaller and more compact Can be a center link type as wellCan be a center link type as well


Power steering Power steering

Used to aid in steering Used to aid in steering Can be hydraulic – uses a pump driven by the Can be hydraulic – uses a pump driven by the

engine, or an electric motor, to pump fluid engine, or an electric motor, to pump fluid through the power steering rack/box to aid through the power steering rack/box to aid driver in turning the steering wheeldriver in turning the steering wheel

Can be electric – uses electric motor mounted Can be electric – uses electric motor mounted on rack/box to help driver turn the steering on rack/box to help driver turn the steering wheel wheel


Power steering Power steering


Electronic power steeringElectronic power steering


4 wheel steering 4 wheel steering

Used by some manufacturers to aid Used by some manufacturers to aid handlinghandling

Front wheels do most of the steering Front wheels do most of the steering At low speeds, rear wheels steer At low speeds, rear wheels steer

opposite front to tighten turning radiusopposite front to tighten turning radius At high speeds, rear wheels turn with At high speeds, rear wheels turn with

front to improve handling and corneringfront to improve handling and cornering



Can be hydraulic or electricCan be hydraulic or electric Front steering is usually “normal” power Front steering is usually “normal” power

steering steering Rear wheel steering can be driven Rear wheel steering can be driven

hydraulically or by electric motorhydraulically or by electric motor



3000GT VR4 All Wheel Steering demo – YouTube

steering systems

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