Suspension SystemsSuspension Systems

Consumer AutoConsumer Auto

What is a Suspension System?What is a Suspension System?

It supports the weight of the carIt supports the weight of the car It keeps tires in firm contact with roadIt keeps tires in firm contact with road It prevents body roll when corneringIt prevents body roll when cornering It keeps the wheels in alignmentIt keeps the wheels in alignment

Typical Suspension System Typical Suspension System PartsParts

Control armControl arm SpringSpring ShockShock Ball jointBall joint KnuckleKnuckle

Control ArmsControl Arms

Can be an arm that in the shape of an Can be an arm that in the shape of an “A” (purple)“A” (purple)

Some are a heavy duty rodSome are a heavy duty rod Used to keep the tires in alignmentUsed to keep the tires in alignment

SpringsSprings Front springs are Front springs are

usually coil springs (10)usually coil springs (10) Rear springs can be Rear springs can be

coil or leaf springs (11)coil or leaf springs (11) Some springs are a Some springs are a

round bar called a round bar called a torsion bartorsion bar

Used to hold the weight Used to hold the weight of the carof the car

Ball JointBall Joint

Mounted in the control Mounted in the control arm, it lets the tire turn as arm, it lets the tire turn as well as go up and down at well as go up and down at the same timethe same time

The other end mounts to The other end mounts to the spindlethe spindle

Steering Knuckle (Blue Green)Steering Knuckle (Blue Green)

Holds the tire to the car Holds the tire to the car using a spindleusing a spindle

Attaches to the lower Attaches to the lower control arm and the control arm and the strut or upper control strut or upper control armarm

Connects to the tie Connects to the tie rods for steeringrods for steering

Shock AbsorberShock Absorber

Stops the car from bouncing excessivelyStops the car from bouncing excessively Helps prevent rapid tire wearHelps prevent rapid tire wear Does not support the weight of the carDoes not support the weight of the car

Types of Suspension SystemsTypes of Suspension Systems

Short Arm/Long Arm McPherson StrutShort Arm/Long Arm McPherson Strut

Short Arm/Long Arm Short Arm/Long Arm Suspension PartsSuspension Parts

Upper & lower control armsUpper & lower control arms Upper & lower ball jointUpper & lower ball joint Steering knuckleSteering knuckle Coil springCoil spring ShockShock Stabilizer bar & linkStabilizer bar & link

Short Arm/Long Arm Short Arm/Long Arm Suspension OperationSuspension Operation

Control arms mounted to frame and the Control arms mounted to frame and the steering knuckle steering knuckle

Upper arm shorter than lower, making Upper arm shorter than lower, making them unequal in lengththem unequal in length

Provides a way for the tires to maintain Provides a way for the tires to maintain traction with the road when the car goes traction with the road when the car goes over bumpsover bumps

McPherson Strut Suspension PartsMcPherson Strut Suspension Parts

McPherson strutMcPherson strut Coil springCoil spring Lower control armLower control arm KnuckleKnuckle Stabilizer barStabilizer bar Strut rodStrut rod

McPherson Strut OperationMcPherson Strut Operation

Coil spring & shock are combinedCoil spring & shock are combined The upper control arm is replaced by the The upper control arm is replaced by the

McPherson strutMcPherson strut Less parts and weight which gives better Less parts and weight which gives better

gas mileagegas mileage Not a heavy duty suspension systemNot a heavy duty suspension system Used on smaller carsUsed on smaller cars

Shock AbsorbersShock Absorbers

Used on SLA systemsUsed on SLA systems Dampens the rebound of the springDampens the rebound of the spring Stops spring oscillationsStops spring oscillations Provides resistance one way (extending)Provides resistance one way (extending) Can wear outCan wear out

Shock Absorber InspectionShock Absorber Inspection

Look at the shock for signs of damageLook at the shock for signs of damage Look for leaking fluid from the ram endLook for leaking fluid from the ram end Test the operation by jumping on the car Test the operation by jumping on the car

to see if it bounces more than onceto see if it bounces more than once Replace the shock if it is bad Replace the shock if it is bad Replace in pairsReplace in pairs

Air Shocks Air Shocks

Used to adjust height or help sagging Used to adjust height or help sagging springssprings

Used on rear Used on rear Air added and Air added and

released released manuallymanually

Automatic Load Leveling Automatic Load Leveling Systems Systems

Usually a four wheel systemUsually a four wheel system Has an air pump and sensors that monitor Has an air pump and sensors that monitor

the ride heightthe ride height Air added & released automatically as Air added & released automatically as

neededneeded

Active Suspension Systems Active Suspension Systems

Springs & shocks replaced with actuatorsSprings & shocks replaced with actuators Actuators work by hydraulicsActuators work by hydraulics They adjust the height of the car and the They adjust the height of the car and the

stiffness of the ridestiffness of the ride Sensors automatically correct ride without Sensors automatically correct ride without

input from the driverinput from the driver

ReviewReview

1.1. Do shocks correct ride height?Do shocks correct ride height?2.2. What are the 2 types of springs?What are the 2 types of springs?3.3. Active suspension replaces springs and Active suspension replaces springs and

shocks with this part.shocks with this part.4.4. SLA stands for what?SLA stands for what?5.5. What part does the McPherson strut What part does the McPherson strut

suspension not have?suspension not have?

ReviewReview

6.6. What is the purpose of the ball joint?What is the purpose of the ball joint?7.7. Why do we need springs in the Why do we need springs in the

suspension?suspension?8.8. In what type of car is McPherson strut In what type of car is McPherson strut

suspension used?suspension used?9.9. What is one reason why we have What is one reason why we have

suspension systemssuspension systems10.10. The spindle attaches to what 2 parts?The spindle attaches to what 2 parts?