2B – 2IWHEEL 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:
S The front tire wear is different from the rear.
S The left and right front tire wear is unequal.
S The left and right rear tire wear is unequal.
Check wheel alignment if:
S The left and right front tire wear is unequal.
S The wear is uneven across the tread of either front
tire.
S The 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 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.
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 substi–tut-
ing 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 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.
