WHEEL ALIGNMENT 2B – 3
DAEWOO V–121 BL4
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 pathon a level road with no pressure on the steering wheel.
Lead is usually caused by:
S Incorrect alignment.
S Uneven brake adjustment.
S 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 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.
2B – 10IWHEEL ALIGNMENT
DAEWOO V–121 BL4
GENERAL DESCRIPTION
AND SYSTEM OPERATION
FOUR WHEEL ALIGNMENT
The first responsibility of engineering is to design safe
steering and suspension systems. Each component must
be strong enough to withstand and absorb extreme pun-
ishment. Both the steering system and the front and the
rear suspension must function geometrically with the body
mass.
The steering and the suspension systems require that the
front wheels self–return and that the tire rolling effort and
the road friction be held to a negligible force in order to al-
low the customer to direct the vehicle with the least effort
and the most comfort.
A complete wheel alignment check should include mea-
surements of the rear toe and camber.
Four–wheel alignment assures that all four wheels will be
running in precisely the same direction.
When the vehicle is geometrically aligned, fuel economy
and tire life are at their peak, and steering and perfor-
mance are maximized.
TOE
Toe–in is the turning in of the tires, while toe–out is the
turning out of the tires from the geometric centerline or
thrust line. The toe ensures parallel rolling of the wheels.
The toe serves to offset the small deflections of the wheel
support system which occur when the vehicle is rolling for-
ward. The specified toe angle is the setting which achieves
0 degrees of toe when the vehicle is moving.
Incorrect toe–in or toe–out will cause tire wear and re-
duced fuel economy. As the individual steering and sus-
pension components wear from vehicle mileage, addition-
al toe will be needed to compensate for the wear.
Always correct the toe dimension last.
CASTER
Caster is the tilting of the uppermost point of the steering
axis either forward or backward from the vertical when
viewed from the side of the vehicle. A backward tilt is posi-
tive, and a forward tilt is negative. Caster influences direc-
tional control of the steering but does not affect tire wear.
Weak springs or overloading a vehicle will affect caster.
One wheel with more positive caster will pull toward the
center of the car. This condition will cause the car to move
or lean toward the side with the least amount of positive
caster. Caster is measured in degrees and is not adjust-
able.
CAMBER
Camber is the tilting of the top of the tire from the vertical
when viewed from the front of the vehicle. When the tires
tilt outward, the camber is positive. When the tires tilt in-
ward, the camber is negative. The camber angle is mea-
sured in degrees from the vertical. Camber influences
both directional control and tire wear.
If the vehicle has too much positive camber, the outside
shoulder of the tire will wear. If the vehicle has too much
negative camber, the inside shoulder of the tire will wear.
Camber is not adjustable.
STEERING AXIS INCLINATION
Steering Axis Inclination (SAI) is the tilt at the top of the
steering knuckle from the vertical. Measure the SAI angle
from the true vertical to a line through the center of the strut
and the lower ball joint as viewed from the front of the ve-
hicle.
SAI helps the vehicle track straight down the road and as-
sists the wheel back into the straight ahead position. SAI
on front wheel drive vehicles should be negative.
INCLUDED ANGLE
The included angle is the angle measured from the cam-
ber angle to the line through the center of the strut and the
lower ball joint as viewed from the front of the vehicle.
The included angle is calculated in degrees. Most align-
ment racks will not measure the included angle directly. To
determine the included angle, subtract the negative or add
the positive camber readings to the Steering Axis Inclina-
tion (SAI).
SCRUB RADIUS
The scrub radius is the distance between true vertical and
the line through the center of the strut and lower ball joint
to the road surface. Scrub radius is built into the design of
the vehicle. Scrub radius is not adjustable.
SETBACK
The setback is the distance in which one front hub and
bearing assembly may be rearward of the other front hub
and bearing assembly. Setback is primarily caused by a
road hazard or vehicle collision.
TURNING ANGLE
The turning angle is the angle of each front wheel to the
vertical when the vehicle is making a turn.
ZF 4 HP 16 AUTOMATIC TRANSAXLE 5A1 – 49
DAEWOO V–121 BL4
Functional Check Procedure
Inspect
1. Install a tachometer or scan tool.
2. Operate the vehicle unit proper operating tempera-
ture is reached.
3. Drive the vehicle at 80 to 88km/h (50 to 55 mph)
with light throttle(road load).
4. Maintaining throttle position, lightly touch the brake
pedal and check for release of the TCC and a slight
increase in engine speed(rpm).
5. Release the brake slowly accelerate and check for
a reapply of the Lock up clutch and a slight de-
crease in engine speed(rpm).
Torque Converter Evaluation
Torque Converter Stator
The torque converter stator roller clutch can have one of
two different type malfunctions :
A. Stator assembly freewheels in both directions.
B. Stator assembly remains Locked up at all times.
Condition A – Poor Acceleration Low
Speed
The car tends to have poor acceleration from a stand still.
At speeds above 50 to 55km/h(30 to 35mph), the car may
act normal. If poor acceleration is noted, it should first be
determined that the exhaust system is not blocked, and
the transaxle is in 1st(First) gear when starting out.
If the engine freely accelerates to high rpm in N(Neutral),
it can be assumed that the engine and exhaust system are
normal. Checking for poor performance in ”Drive” and ”Re-
verse” will help determine if the stator is freewheeling at all
times.
Condition B – Poor Acceleration High
Speed
Engine rpm and car speed limited or restricted at high
speeds. Performance when accelerating from a standstill
is normal. Engine may overheat. Visual examination of the
converter may reveal a blue color from overheating.
If the converter has been removed, the stator roller clutch
can be checked by inserting two fingers into the splined in-
ner race of the roller clutch and trying to turn freely clock-
wise, but not turn or be very difficult to turn counter clock-
wise.
Noise
Torque converter whine is usually noticed when the ve-
hicle is stopped and the transaxle is in ”Drive” or ”Re-
verse”. The noise will increase when engine rpm is in-
creased. The noise will stop when the vehicle is moving or
when the torque converter clutch is applied because both
halves of the converter are turning at the same speed.
Perform a stall test to make sure the noise is actually com-
ing from the converter :1. Place foot on brake.
2. Put gear selector in ”Drive”.
3. Depress accelerator to approximately 1200rpm for
no more than six seconds.
Notice : If the accelerator is depressed for more than six
seconds, damage to the transaxle may occur.
A torque converter noise will increase under this load.
Important : This noise should not be confused with pump
whine noise which is usually noticeable in P (Park), N
(Neutral) and all other gear ranges. Pump whine will vary
with pressure ranges.
The torque converter should be replaced under any of the
following conditions:
S External leaks in the hub weld area.
S Converter hub is scored or damaged.
S Converter pilot is broken, damaged or fits poorly
into crankshaft.
S Steel particles are found after flushing the cooler
and cooler lines.
S Pump is damaged or steel particles are found in the
converter.
S Vehicle has TCC shudder and/or no TCC apply.
Replace only after all hydraulic and electrical diag-
noses have been made.(Lock up clutch material
may be glazed.)
S Converter has an imbalance which cannot be cor–
rected. (Refer To Converter Vibration Test Proce-
dure.)
S Converter is contaminated with engine coolant con-
taining antifreeze.
S Internal failure of stator roller clutch.
S Excess end play.
S Heavy clutch debris due to overheating (blue con-
verter).
S Steel particles or clutch lining material found in fluid
filter or on magnet when no internal parts in unit are
worn or damaged(indicates that lining material
came from converter).
The torque converter should not be replace if :
S The oil has an odor, is discolored, and there is no
evidence of metal or clutch facing particles.
S The threads in one or more of the converter bolt
holes are damaged.
–correct with thread insert.
S Transaxle failure did not display evidence of dam-
age or worn internal parts, steel particles or clutch
plate lining material in unit and inside the fluid filter.
S Vehicle has been exposed to high mileage(only).
The exception may be where the Lock up clutch
damper plate lining has seen excess wear by ve-
hicles operated in heavy and/or constant traffic,
such as taxi, delivery or police use.
Lock–Up Clutch Shudder Diagnosis
The key to diagnosing lock–up clutch(TCC) shudder is to
note when it happens and under what conditions.