08 Suspension System
08 Suspension System
1. SPECIFICATIONS
Description Specification
Suspension type Double wishbone
2. WHEEL ALIGNMENT
Toe-in YG·GYGGW¥[G
LH TWUX`¶G·GWUY\¶G
Front Camber
Wheel RH TWUY`¶G·GWUY\¶G
Alignment
LH [U[¶G·GWU[¶G
Caster
RH [U\¶G·GWU[¶G
ࣰࣩ࣬ࣴ
Shock absorber
ඖ Top View
Stabilizer bar
Shock absorber
Lateral rod
Axle housing
Lateral rod
Tightening torque: 150 ~ 180 Nm
5. TROUBLESHOOTING
Problem Cause Action
Broken stabilizer bar Replace
Vehicle rolling
Faulty shock absorber Replace
Loosening mounting Retighten
Damaged or worn wheel bearing Replace
Abnormal noise.
Damaged shock absorber Replace
Damaged tire Replace
Over inflated tire Adjust pressure
Faulty shock absorber Replace
Loosened wheel nut Tighten as specified torque
Poor riding
Bent or broken coil spring Replace
Damaged tire Replace
Worn bushing Replace
Deformed arm assembly Replace
Vehicle pulls to one side Worn bushing Replace
Bent or broken coil spring Replace
Excessive resistance of lower arm Replace
Hard steering ball joint
Insufficient tire pressure Replace
Faulty power steering Replace
Unstable steering Worn or loosened lower arm Retighten or replace
bushing
Vehicle bottoming Worn or broken coil spring Replace
Over loaded on the vehicle -
Vehicle height lowered Defective shock absorber Replace
Defective coil spring Replace
4411-01 ࣩ࣬ࣴࣵ
1. SUSPENSION
The suspension is the device to connect the axle and vehicle. It absorbs the vibrations and
impacts from road surface, which enhances the comforts, driving force, braking force and
drivability.
Front suspension
Rear suspension
ࣩ࣭࣬ࣴ࣬
ඖ Advantage
1. The advantage of a double wishbone suspension is that it is fairly easy to work out the effect
of moving each joint, so the kinematics of the suspension can be tuned easily and wheel
motion can be optimized.
2. It is also easy to work out the loads that different parts will be subjected to which allows more
optimized lightweight parts to be designed.
3. They also provide increasing negative camber gain all the way to full jounce travel unlike the
MacPherson strut which provides negative camber gain only at the beginning of jounce travel
and then reverses into positive camber gain at high jounce amounts.
ඖ Disadvantage
1. The disadvantage is that it is slightly more complex than other systems like a MacPherson strut.
2. Due to the increased number of components within the suspension setup it takes much longer to
service and is heavier than an equivalent MacPherson design.
4411-01 ࣩ࣭࣭࣬ࣴ
4. WHEEL ALIGNMENT
The front wheels have specific angle to allow control of the steering wheel with less effort, ensure
driving stability, improve steering wheel restoration and steering performance, and minimize the
tires wear.
1) Toe-in
The difference of measured distances between the front ends of the tires (A) and the rear ends of
the tires (B) along the same axle when viewed the wheels from the top
Front
Toe-in YG·GYGGOW¥[GP
ඖ When viewed from the top, the distance between the tire centers is smaller in the front than in
the rear.
2) Camber
The angle between the center line of the tire and the vertical line when viewed from the front of
the vehicle
LH TWUX`¶G·GWUY\¶G
Camber
RH TWUY`¶G·GWUY\¶G
ඖ Zero camber: When the tire center line is perpendicular to the ground level
ඖ Negative camber
Advantages: - Better traction force due to wide load area (applicable for off-road vehicle)
- Better corner driving when the vehicle makes turn as the cornering force
Disadvantages: increases (applicable for high-speed F1 vehicle)
- he axle is easy to be bent or deviated in the negative camber than in
the positive camber when load is applied on the axle.
- Difficult to control due to wide load area.
ࣰࣩ࣭࣬ࣴ
3) Caster
The angle between the vertical line and king pin, which fixes the steering knuckle and front axle,
(steering column which connects the top and bottom ball joints in the independent axle type)
when viewed the tires from the side.
LH [U[¶G·GWU[¶G
Caster
RH [U\¶G·GWU[¶G
ඖ Caster: With considering the height difference between the wheel centers of the front and rear
wheels. (Under standard condition that the vehicle is on a level ground)
ඖ Positive caster:Top of the king pin is tilted backward from the vertical line of the wheel center
when viewed the tires from the side
Advantages: - Directional force to go straight (following control)
- Restoring force of the wheel (restored to the straight ahead direction)
- Prevention of wheel shimmy (wheels wobble left and right)
ඖ Negative caster: Top of the king pin is tilted forward from the vertical line of the wheel center
when viewed the tires from the side
Advantages: - Smaller turning radius
Disadvantages: - Impact from the road is transferred to the steering wheel (steering wheel
turns)
- Poor straightness
4411-01 ࣱࣩ࣭࣬ࣴ
1) Overview
The shock absorber is connected to the piston rod in the strut. This relieves the vertical vibrations
of vehicle to provide ride comforts, prevents the spring break, enhances drivability, and extends
the life span of steering components.
Stabilizer bar
Coil spring
Yoke
Shock absorber
ࣲࣩ࣭࣬ࣴ
3) Sectional Diagram
4) Operating Process
The telescopic shock absorber consists of a tube with piston and rod and a cylinder tube. The
piston has an orifice and valve and the cylinder is filled with oil. The double action cylindrical type
shock absorber restrains the vibrations by using oil resistance. This provides better drivability even
though the structure is complicated. This vehicle uses the gas shock absorber.
4410-10 ࣩ࣭࣬ࣴࣳ
1) Overview
The upper arm is mounted to the frame and the knuckle and it relieves the load delivered from the
tire to the knuckle. This enables to absorb the various impacts according to the load shapes and
to ensure the drivability.
Cotter pin
Castle nut
Balll joint
Lower arm
Bolt/nut
ࣩ࣭࣬ࣴࣴ
1) Overview
The lower arm is mounted to the knuckle, the shock absorber and the lower arm assembly.
It relieves the load delivered from the tire to the knuckle. This enables to absorb the various
impacts according to the load shapes and to ensure the drivability.
Front knuckle
Lower arm
Front bushing
Rear bushing
Bolt/nut
Yoke connection
4420-01 ࣩ࣭࣬ࣴࣵ
1) Overview
If the spring with lower spring constant is applied on the vehicle in order to increase the "ride
comforts", the vehicle's slope increases on turning due to the centrifugal force. Because its trend
increases for the independent suspension system, the stabilizer bar should be applied to the
system in order to make a balance the vehicle. The stabilizer bar is a certain type of torsion bar. Its
both ends are connected to the control arm and the its center area is mounted to the body frame.
It is not activated when both wheels are moving up or down simultaneously. However, it minimizes
the vehicle's slope when each wheel moves up or down independently.
Under cover
Stabilizer bar
Stabilizer bar
Link
Link bushing
ࣩ࣮࣬ࣴ࣬
1) Overview
The coil spring is made by winding solid steel rod to form the coil shape. Its energy absorption
rate per weight is higher than that of the leaf spring and it allows to absorb small vibration properly
resulted in keeping the ride comforts. Therefore, it's difficult to make an effect on vibration
damping because there is not any friction between coils.
2) Layout
Spring for 2WD Spring for 4WD
Variation
1) Overview
It absorbs the vertical vibration of the vehicle body. It enhances the ride comforts and prevents
the fatigue break of the spring.
Lock nut
Upper washer
Center washer
Lower mounting bushing
Lower washer
Dust cover
1) Overview
It compensates the longitudinal load to the vehicle.
Upper arm
Lower arm
1) Overview
It compensates the transverse load to the vehicle.
Lateral Rod
Screw
Lock nut
Lateral rod
Rubber bushing
ࣰࣩ࣮࣬ࣴ
1) Overview
It is installed between the rear axle and body frame. It relieves the vibrations and impacts delivered
from wheels to vehicle body.
Bumper stopper
1) Overview
pGGGGGGGGSGG¡GG˅GGGG
GGGGGG GGGG˅G U
Stabilizer Bar
Stabilizer bar
Upper Arm
Shock Absorber
Shock
absorber Lock bolt
assembly
Yoke
Lower arm
ࣩ࣯࣮࣬ࣴ
Height adjust
Locking bar
4411-02 ࣩ࣯࣯࣬ࣴ
Dust cover
Lock nut
Coil spring
Bumper stopper
Shock absorber
ࣲࣩ࣯࣬ࣴ
Make sure to align the recess (A) of lower seat with the recess (B) of upper insulator.
Otherwise, it cannot be installed on the vehicle properly.
4420-01 ࣩ࣯࣬ࣴࣳ
Stabilizer bar
Washer
Bushing
Vehicle outside
Stabilizer bar
Link
Link bushing
ࣰࣩ࣬ࣴ࣬
Lower Arm
- Interference
Camber adjusting
bolt/nut
Lower arm
to yoke
4510-13 ࣰࣩ࣯࣬ࣴ
Stabilizer Bar
1) Lower Arm
1. Support the bottom of rear axle housing
with a safety jack.
2) Upper Arm
Shock Absorber
Inspection
ͽ
ࣱࣩ࣮࣬ࣴ
Coil Spring
Bumper stopper