Page 818 of 1463

SUSPENSION DIAGNOSIS 2A-3
DIAGNOSIS
GENERAL DIAGNOSIS
Checks
Loosened Mountings
Damaged or Worn wheel Bearing
Damaged Shock Absorber
Damaged TireAction
Retightening
Replace
Replace
Replace
Abnormal Noises
Checks
Broken Stabilizer Bar
Faulty Shock AbsorberAction
Replace
Replace
Vehicle Rolling
Checks
Over Inflated Tire
Faulty Shock Absorber
Loosened wheel Nut
Bent or Broken Coil Spring
Damaged Tire
Worn BushingAction
Pressure Adjustment
Replace
Tighten as Specified
Replace
Replace
Replace
Poor Riding
Problems in the steering, the suspension, the tires, and
the wheels involve several systems. Consider all systems
when you diagnose a complaint. Some problems, such
as abnormal or excessive tire wear and scuffed tires,
may by the result of hard driving. Always road test thevehicle first. If possible, do this road test with the
customer.
Proceed with the following preliminary checks. Correct
any substandard conditions.
Checks
Incorrect Wheel Alignment
Excessive Resistance of Lower Arm Ball Joint
Insufficient Tire Pressure
Faulty Power Steering
Action
Repair
Replace
Adjust
Repair or Replace
Hard Steering
Checks
Deformed Arm Assembly
Worn Bushing
Bent or Broken Coil Spring
Difference Between L/H & R/H HeightsAction
Replace
Replace
Replace
Adjust
Vehicle Pulls to Right or Left
Page 819 of 1463
2A-4 SUSPENSION DIAGNOSIS
Checks
Worn or Broken Coil SpringChecks
Incorrect Front wheel Alignment
Worn or Loosened Lower Arm Bushing
Action
Replace
Repair or Replace
Steering Instability
Action
Replace
Vehicle Bottoming
Page 829 of 1463

SECTION 2B
WHEEL ALIGNMENT
TABLE OF CONTENTS
SPECIFICATIONS
WHEEL ALIGNMENT SPECIFICATIONS
Application
Camber
Caster
Toe-in
King Pin InclinationDescription
0° ± 30'
2°30' ± 30'
0 - 4 mm
12°30'
Specifications . . . . . . . . . . . . . . . . . . . . . . . . 2B-1
Wheel Alignment Specifications . . . . . . . . . . . 2B-1
Diagnosis . . . . . . . . . . . . . . . . . . . . . . . . . . . 2B-2
Tire Diagnosis . . . . . . . . . . . . . . . . . . . . . . . . . 2B-2
Radial Tire Lead/Pull . . . . . . . . . . . . . . . . . . . 2B-3
Vibration Diagnosis . . . . . . . . . . . . . . . . . . . . . 2B-5
Maintenance and Repair . . . . . . . . . . . . . . . 2B-6
On-Vehicle Service . . . . . . . . . . . . . . . . . . . . . . 2B-6Wheel Alignment . . . . . . . . . . . . . . . . . . . . . . . 2B-6
General Description and System
Operation . . . . . . . . . . . . . . . . . . . . . . . . . 2B-9
Four Wheel Alignment . . . . . . . . . . . . . . . . . . 2B-9
Toe . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2B-9
Caster . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2B-9
Camber . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2B-9
Page 830 of 1463

2B-2 WHEEL ALIGNMENT
DIAGNOSIS
TIRE DIAGNOSIS
Irregular and Premature Wear
Irregular and premature tire wear has many causes.
Some of them are incorrect inflation pressures, lack of
regular rotation, poor driving habits, or improper wheel
alignment.
Rotate the tires if :
lThe front tire wear is different from the rear.
lThe left and right front tire wear is unequal.
lThe left and right rear tire wear is unequal, Check
wheel alignment if :
lThe left and right front tire wear is unequal.
lThe wear is uneven across the tread of either front
tire.
lThe front tire treads are scuffed with “feather” edges
on the side of the tread ribs or blocks.
Tread Wear Indicators
The original equipment tires have built-in tread wear
indicators to show when the tires need replacement.
These indicators appear as bands when the tire tread
depth becomes shallow. Tire replacement is
recommended when the indicators appear in three or
more grooves at six locations.
Radial Tire Waddle
Waddle is side-to-side movement at the front or rear of
the vehicle. It is caused by the steel belt not being straight
within the tire, or by excessive lateral runout of the tire
or wheel.
The vehicle must be road tested to determine which end
of the vehicle has the faulty tire. The rear end of the
vehicle will shake from side to side or “waddle” if the
waddle tire is on the rear of the vehicle. From the driver’s
seat, it feels as though someone is pushing on the side
of the vehicle. If the faulty tire is on the front of the vehicle,
the waddle is more visual. The front sheet meld appears
to be moving back and forth, and the drivers seat feels
like the pivot point in the vehicle.
Waddle can be diagnosed using the method of
substituting known good tire and wheel assemblies on
the problem vehicle
1. Road test the vehicle to determine if the waddle is
coming from the front or the rear of the vehicle.
2. Install good tires and wheels from a similar vehicle in
place of those on the offending end of the problem
vehicle. If the source of the waddle is not obvious,
change the rear tires.
Page 831 of 1463

WHEEL ALIGNMENT 2B-3
3. Road test the vehicle. If there is improvement, install
the original tires to find the offending tire. If there is
no a straight improvement, install good tires in place
of all four offending tires.
4. Install original tires one at a time to find the offending
tire.
RADIAL TIRE LEAD/PULL
Lead/pull is the deviation of the vehicle from a straight
path on a level road with no pressure on the steering
wheel. Lead is usually caused by:
lIncorrect alignment.
lUneven brake adjustment.
lTire construction.
The way in which a tire is built can produce lead/pull in
the vehicle.011-center belts on radial tires can cause
the tire to develop a side force while the vehicle rolls
straight down the road. If one side of the tire has even a
little larger diameter than the diameter of the other side,
the tire will tend to roll to one side. Unequal diameters
will cause the tire to develop a side force which can
produce vehicle lead/pull.
The radial lead/pull diagnosis chart should be used to
determine whether the problem originates from an
alignment problem or from the tires. Part of the lead
diagnosis procedure calls for tire rotation that is different
from the proper tire rotation pattern. If a medium- to high-
mileage tire is moved to the other side of the vehicle, be
sure to check for ride roughness. Rear tires will not cause
lead/pull.
Page 832 of 1463

2B-4 WHEEL ALIGNMENT
1. Perform wheel alignment preliminary inspection.
2. Check the brakes for dragging.
3. Road test the vehicle.
Does the vehicle lead/pull?
1. Cross switch the front tire and wheel assemblies.
2. Road test the vehicle.
Does the vehicle lead/pull?
1. Check the front wheel alignment.
Is the alignment within specifications?
1. Compare the front camber and front caster to
specifications.
Are they within specifications?
1. Check the vehicle frame.
Is the frame bent?
1. Straighten the frame.
Is the repair complete?
1. The probable cause is the tires.
2. Switch the left front tire and wheel assembly with
the left rear tire and wheel assembly.
3. Road test the vehicle.
Does the vehicle still lead/pull?
1. Switch the left front tire and wheel assembly with
the left rear tire and wheel assembly and replace the
left front tire.
Does the repair complete?
1. Switch the right front tire and wheel assembly with
the right rear tire and wheel assembly.
2. Road test the vehicle.
Does the vehicle still lead/pull?
1. Switch the right front tire and wheel assembly with
the right rear tire and wheel assembly and replace
the right front tire.
Is the repair complete?Action
Radial Tire Lead/Pull Diagnosis Chart
Step
1Values(s)
-Yes
Go to
Step 2
Go to Step 3
Go to Step 4
Go to Step 7
Go to Step 6
Go to Step 3
Go to Step 9
System OK
Go to
Step 1
System OKNo
System OK
System OK
Adjust
alignment
Go to
Step 5
Go to Step 1
-
Go to
Step 8
Go to Step 1
Go to Step 10
Go to Step 1
2
3
4
5
6
7
8
9
10-
-
-
-
-
-
-
-
-
Page 833 of 1463

WHEEL ALIGNMENT 2B-5
VIBRATION DIAGNOSIS
Wheel imbalance causes most highway speed vibration
problems. A vibration can remain after dynamic
balancing because:
lA tire is out of round.
lA rim is out of round.
lA tire stiffness variation exists.
Measuring tire and wheel free runout will uncover only
part of the problem, All three causes, known as loaded
radial runout, must be checked using method of
substituting known good tire and wheel assemblies on
the problem vehicle.
Preliminary Checks
Prior to performing any work, always road test the car
and perform a careful visual inspection for:
lObvious tire and wheel runout.
lObvious drive axle runout.
lImproper tire inflation.
lIncorrect trim height.
lBent or damaged wheels.
lDebris build-up on the tire or the wheel.
lIrregular or excessive tire wear.
lImproper tire bead seating on the rim,
lImperfections in the tires, including: tread
deformations, separations, or bulges from impact
damage. Slight sidewall indentations are normal and
will not affect ride quality.
Tire Balancing
Balance is the easiest procedure to perform and should
be done first if the vibration occurs at high speeds. Do
an off-vehicle, two-plane dynamic balance first to correct
any imbalance in the tire and wheel assembly.
An on-vehicle finish balance will correct any brake drum,
rotor, or wheel cover imbalance, If balancing does not
correct the high-speed vibration, or if the vibration occurs
at low speeds, runout is the probable cause.
Page 834 of 1463
2B-6 WHEEL ALIGNMENT
MAINTENANCE AND REPAIR
ON VEHICLE SERVICE
WHEEL ALIGNMENT
Vehicle Height
1. Check the tire for proper inflation.
2. Measure ‘A’ from the center of the lower arm rear mounting
bolt end to the ground.
3. Measure ‘B’ from the center of the steering knuckle shaft to
the ground.
4. If the difference between ‘A’ and ‘B’ is not within specification,
adjust vehicle height using torsion bar height control bolt.
‘B’ - ‘A’
Notice
Before wheel alignment, adjust vehicle height first.
31 - 36mm
Toe-in
1. Measure toe-in.
Specification0 - 4mm
2. If toe-in is not within specification, loosen the tie rod nuts
and adjust it by turning the tie rod.