Daewoo Nubira. Service manual - part 255

2B – 2

I

WHEEL ALIGNMENT

DAEWOO V–121 BL4

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.
If the wheel alignment is reset because of tire wear, always
reset the toe as close to zero degrees as the specification
allows. Refer to ”Rear Toe Adjustment” in this section.

Rotate the tires if

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The front tire wear is different from the rear.

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The left and right front tire wear is unequal.

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The left and right rear tire wear is unequal.

Check wheel alignment if:

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The left and right front tire wear is unequal.

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The wear is uneven across the tread of either front
tire.

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The front tire treads are scuffed with ”eather”edges
on the side of the tread ribs or blocks.

Tread Wear Indicators

The original equipment tires have built–in tread wear indi-
cators to show when the tires need replacement. These in-
dicators appear as bands when the tire tread depth be-
comes shallow. Tire replacement is recommended when
the indicators appear in three or more grooves at six loca-
tions.

WHEEL ALIGNMENT  2B – 3

DAEWOO V–121 BL4

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. It is most noticeable at low speeds, 8 to 48 km/h (5
to 30 mph), but may appear as ride roughness at 80 to 113
km/h (50 to 70 mph).

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 metal appears to be moving
back and forth, and the driver

’

s 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 ve-
hicle.

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 prob-
lem vehicle. If the source of the waddle is not ob-
vious, change the rear tires.

3.  Road test the vehicle. If there is improvement,

install the original tires to find the offending tire. If
there is no improvement, install good tires in place
of all four offending tires.

4.  Install original tires one at a time to find the offend-

ing 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:

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 Incorrect 

alignment.

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Uneven brake adjustment.

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 Tire 

construction.

The way in which a tire is built can produce lead/pull in the
vehicle. Off–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 diam-
eter 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 de-
termine whether the problem originates from an alignment
problem or from the tires. Part of the lead diagnosis proce-
dure calls for tire rotation that is different from the proper
tire rotation pattern. If a medium– to highmileage tire is
moved to the other side of the vehicle, be sure to check for
ride roughness. Rear tires will not cause lead/pull.

2B – 4

I

WHEEL ALIGNMENT

DAEWOO V–121 BL4

Radial Tire Lead/Pull Diagnosis Chart

Step

Action

Value(s)

Yes

No

1

1.  Perform wheel alignment preliminary inspec-

tion.

2.  Check the brakes for dragging.
3.  Road test the vehicle.

Does the vehicle lead/pull?

Go to Step 2 

System OK

2

1.  Cross switch the front tire and wheel assem-

blies.

2.  Road test the vehicle.

Does the vehicle lead/pull?

Go to Step 3 

System OK

3

Check the front wheel alignment.
Is the alignment within specifications?

Go to Step 4 

Adjust align-

ment

4

Compare the front camber and front caster to speci-
fications.
Are they within specifications?

 Go to Step 7

 Go to Step 5

5

Check the vehicle frame.
Is the frame bent?

 Go to Step 6 

 Go to Step 1

6

Straighten the frame.
Is the repair complete?

Go to Step 3

7

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?

 Go to Step 9

Go to Step 8

8

Switch the left front tire and wheel assembly with the
left rear tire and wheel assembly and replace the left
front tire.
Is the repair complete?

System OK

Go toStep 1

9

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?

Go to Step 1

Go to Step 10 

10

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?

System OK

 Go to Step 1

WHEEL ALIGNMENT  2B – 5

DAEWOO V–121 BL4

VIBRATION DIAGNOSIS

Wheel imbalance causes most highway speed vibration
problems. A vibration can remain after dynamic balancing
because:

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A tire is out of round.

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A rim is out of round.

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A 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 ve-
hicle.

Low–speed vibrations, which occur below 64 km/h (40
mph), are usually caused by runout. High–speed vibra-
tions, which occur above 64 km/h (40 mph), can be caused
by either imbalance or runout.

Preliminary Checks

Prior to performing any work, always road test the car and
perform a careful visual inspection for:

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Obvious tire and wheel runout.

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Obvious drive axle runout.

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Improper tire inflation.

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Incorrect trim height.

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Bent or damaged wheels.

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Debris build–up on the tire or the wheel.

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Irregular or excessive tire wear.

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Improper tire bead seating on the rim.

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Imperfections in the tires, including tread deforma-
tions, 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 im-
balance 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 cor-
rect the high–speed vibration, or if the vibration occurs at
low speeds, runout is the probable cause.

Runout

Runout can be caused by the tire, the wheel, or the way
the wheel is attached to the vehicle. To investigate the pos-
sibility of wheel runout, refer to the following procedures
as well as the wheel runout diagnosis chart in this section:

1.  If runout is suspected, measure the on–vehicle free

lateral and free radial runout of the tire and wheel
assembly. Refer to Section 2E, Tires and Wheels. 
Both the free lateral and the free radial runout