2A – 2ISUSPENSION DIAGNOSIS
DAEWOO V–121 BL4
Abnormal or Excessive Tire Wear
ChecksAction
Check the front–wheel and the rear–wheel alignment.Align the front and the rear wheels.
Inspect for excessive toe on the front and the rear wheels.Adjust the toe on the front and the rear wheels.
Inspect for a broken or a sagging spring.Replace the spring.
Inspect for out–of–balance tires.Balance the tires.
Inspect for worn strut dampeners.Replace the strut dampeners.
Check for a failure to rotate tires.Rotate the tires. Replace the tires as needed.
Check for an overloaded vehicle.Maintain the proper load weight.
Inspect for low tire inflation.Inflate the tires to the proper pressure.
Scuffed Tires
ChecksAction
Inspect for incorrect toe on the front and the rear wheels.Adjust the toe on the front and the rear wheels.
Inspect for a twisted or a bent suspension arm.Replace the suspension arm.
Wheel Tramp
ChecksAction
Inspect for an out–of–balance tire or wheel.Balance the tire or the wheel.
Inspect for improper strut dampener action.Replace the strut dampeners.
Shimmy, Shake, or Vibration
ChecksAction
Inspect for an out–of–balance tire or wheel.Balance the tire or the wheel.
Inspect for excessive wheel hub runout.Measure the hub flange runout. Replace the hub as need-
ed.
Inspect for excessive brake drum or brake rotor imbal-
ance.Adjust the brakes. Replace the brake rotor or the brake
drum as needed.
Inspect for worn tie rod ends.Replace the outer tie rods.
Inspect for wheel trim imbalance.Balance the wheel.
Inspect for a worn lower ball joint.Replace the lower ball joint.
Inspect for excessive wheel runout.Measure the wheel runout. Replace the wheel as needed.
Inspect for excessive loaded radial runout on the tire and
wheel assembly.Match–mount the tire and wheel assembly.
Hard Steering
ChecksAction
Check the steering gear preload adjustment.Perform a rack bearing preload adjustment.
Check the hydraulic system. Test the power steering sys-
tem pressure with a gauge.Replace the seals and the hoses as needed.
Inspect for binding or catching in the steering gear.Lubricate the steering gear. Repair or replace the steering
gear as needed.
Inspect for a loose steering gear mounting.Tighten the steering gear mounting bracket nuts.
SUSPENSION DIAGNOSIS 2A – 3
DAEWOO V–121 BL4
Too Much Play in Steering
ChecksAction
Inspect for worn or loose wheel bearings.Tighten the drive axle nut. Replace the wheel bearings as
needed.
Inspect for a loose steering gear mounting.Tighten the steering gear mounting bracket nuts.
Inspect the joint from the column to the steering gear for
loose connections or wear.Tighten the intermediate shaft pinch bolts. Replace the in-
termediate shaft as needed.
Check the steering gear preload adjustment.Perform a rack bearing preload adjustment.
Poor Returnability
ChecksAction
Inspect for lack of lubrication of the ball joints and the tie
rod ends.Replace the ball joints and the outer tie rods.
Inspect for binding in the ball joints.Replace the ball joint.
Inspect for binding in the steering column.Lubricate the steering column. Replace the steering col-
umn as needed.
Check the front–wheel alignment.Align the front wheels.
Check the steering gear preload adjustment.Perform a rack bearing preload adjustment.
Inspect for a sticking valve.Lubricate the pinion valve assembly. Replace the pinion
valve assembly as needed.
Inspect for binding in the intermediate shaft on the steering
gear.Replace the intermediate shaft.
Abnormal Noise, Front Suspension
ChecksAction
Inspect for a lack of lubrication of the ball joints and the tie
rod ends.Replace the ball joints and the outer tie rods.
Inspect for damaged suspension components.Replace the damaged suspension components.
Inspect for worn control arm bushings or tie rod ends.Replace the control arm bushings or the tie rods.
Inspect for a loose stabilizer shaft link.Tighten the stabilizer shaft link.
Inspect for loose wheel bolts.Tighten the wheel bolts.
Inspect for loose suspension bolts or nuts.Tighten the suspension bolts or the nuts.
Inspect for worn strut dampeners or strut mountings.Replace the strut dampeners. Tighten the strut mounting
bolts.
Inspect for an improperly positioned strut spring.Adjust the strut spring to the proper position.
Wander or Poor Steering Ability
ChecksAction
Inspect for mismatched or uneven tires.Replace the tires.
Inspect for lack of lubrication of the ball joints and the tie
rod ends.Replace the ball joints and the outer tie rods.
Inspect for worn strut dampeners.Replace the strut dampeners.
Inspect for a loose stabilizer shaft link.Tighten the stabilizer shaft link.
Inspect for a broken or a sagging spring.Replace the spring.
2A – 4ISUSPENSION DIAGNOSIS
DAEWOO V–121 BL4
Checks Action
Check the steering gear preload adjustment.Perform a rack bearing preload adjustment.
Check the front–wheel and the rear–wheel alignment.Align the front and the rear wheels.
Erratic Steering when Braking
ChecksAction
Inspect for worn or loose wheel bearings.Replace the wheel bearings.
Inspect for a broken or a sagging spring.Replace the spring.
Inspect for a leaking wheel cylinder or caliper.Replace the wheel cylinder or the caliper.
Inspect for warped rotors.Replace the rotors.
Inspect for an incorrect or an uneven caster.If the caster is beyond specifications, check the frame and
repair it as needed.
Low or Uneven Trim Height
ChecksAction
Inspect for a broken or a sagging spring.Replace the spring.
Check for an overloaded vehicle.Maintain the proper load weight.
Inspect for an incorrect or weak spring.Replace the spring.
Ride Too Soft
ChecksAction
Inspect for worn strut dampeners.Replace the strut dampeners.
Inspect for a broken or a sagging spring.Replace the spring.
Ride Too Harsh
ChecksAction
Inspect for incorrect strut dampeners.Replace the strut dampeners.
Inspect for an incorrect spring.Replace the spring.
Body Leans or Sways in Corners
ChecksAction
Inspect for a loose stabilizer shaft link.Tighten the stabilizer shaft link.
Inspect for worn strut dampeners or strut mountings.Replace the strut dampeners. Tighten the strut assembly
mounting bolts.
Check for an overloaded vehicle.Maintain the proper load weight.
Inspect for a broken or a sagging spring.Replace the spring.
Suspension Bottoms
ChecksAction
Inspect for worn strut dampeners.Replace the strut dampeners.
Check for an overloaded vehicle.Maintain the proper load weight.
Inspect for a broken or a sagging spring.Replace the spring.
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.
2C – 8IFRONT SUSPENSION
DAEWOO V–121 BL4
1. Cap
2. Strut Upper Nut
3. Piston Rod Nut
4. Strut Mount
5. Strut Bearing
6. Washer
7. Upper Spring Seat
8. Front Spring Locator
9. Upper Spring Insulator
10. Hollow Bumper
11. Front Coil Spring
12. Lower Spring Insulator
13. Front Strut
14. Steering Knuckle–to–Strut Assembly
15. Nut
16. Steering Knuckle
17. Brake Shield
18. Front Hub Bearing19. Outer Snap Ring
20. Front Hub
21. Front Brake Disc
22. Washer
23. Caulking Nut
24. Stabilizer Clamp Bolt
25. Stabilizer Clamp
26. Stabilizer Clamp Insulator
27. Stabilizer
28. Stabilizer Link Nut
29. Stabilizer Link
30. Front Suspension Crossmember
31. Crossmember Cover
32. Crossmember Cover Bolt
33. Crossmember Bolt
34. Crossmember Nut
35. Control Arm
36. Ball Joint
2C – 22IFRONT SUSPENSION
DAEWOO V–121 BL4
Assembly Procedure
1. Press the control arm rear damping bushing into
the control arm using a press and the remover/in-
staller KM–158.
2. Install the split sleeves into the rear control arm
bushing.
3. Install the control arm. Refer to ”Control Arm” in
this section.
FRONT STRUT ASSEMBLY
Tools Required
KM–329–A Spring Compressor
J–42468 Front Strut Mount Nut Wrench
Disassembly Procedure
1. Remove the strut assembly. Refer to ”Strut Assem-
bly” in this section.
2. Fasten the strut assembly to the spring compressor
(DW320–010 or KM–329–A). Make sure the hooks
are seated on the strut spring properly.
3. Compress the front spring with the spring compres-
sor.
4. Use an open end wrench to hold the threaded pis-
ton rod while removing the piston rod nut and the
washer with a commercially available double ring
spanner, sharply offset.
FRONT SUSPENSION 2C – 23
DAEWOO V–121 BL4
Important : Record the position of the front spring locator
relative to the strut assembly–to–knuckle bracket. Place
the front spring locator back in the same position during
assembly.
5. Remove the upper strut mount, the mount bearing,
the upper spring seat, the upper ring insulator, and
the hollow bumper.
6. Release the spring.
7. Remove the spring and the lower ring insulator.
Assembly Procedure
1. Install the lower ring insulator and the spring.
2. Compress the spring using the spring compressor
KM–329–A.
3. Install the hollow bumper, the upper ring insulator,
the front spring locator, the upper spring seat, the
upper strut mount, and the mount bearing. Be sure
the upper spring seat is clipped to the front spring
locator.
4. Install the piston rod nut.
Tighten
Tighten the piston rod nut to 75 NSm (55 lb–ft).
5. Release the spring compresser KM–329–A
KNUCKLE
Disassembly Procedure
1. Remove the knuckle assembly from the vehicle.
Refer to ”Knuckle Assembly” in this section.
2. Remove the rotor. Refer to Section 4D, Front Disc
Brakes.
3. Remove the hub and bearing assembly. Refer to
”Hub and Bearing” in this section.
4. Remove the brake splash shield. Refer to Section
4D, Front Disc Brakes.
FRONT SUSPENSION 2C – 25
DAEWOO V–121 BL4
GENERAL DESCRIPTION
AND SYSTEM OPERATION
FRONT SUSPENSION
The front suspension for this vehicle is a combination of
a strut assembly and a knuckle assembly. The strut as-
sembly combines a strut dampener and spring mounted
to the body of the vehicle. The upper end of the strut is iso-
lated by a rubber mount and contains a bearing to allow the
strut to turn. The knuckle is attached to the strut assembly
and pivots on a ball joint bolted to the control arm. The con-
trol arms pivot from the body using rubber bushings.
The ball joint is fastened to the steering knuckle with a
pinch bolt and nut, and to the lower control arm with rivets.
The stabilizer bar interconnects both strut assemblies ofthe vehicle through the stabilizer link and is attached to the
front suspension crossmember. Jounce and rebound
movements affecting one wheel are partially transmitted
to the opposite wheel of the vehicle to stabilize body roll.
When servicing the control arm–to–body attachment and
the stabilizer shaft–to–body insulators, make sure the at-
taching bolts are loose until the control arms are moved to
the trim height, which is curb height. Trim height is the nor-
mal position to which the control arms move when the ve-
hicle is sitting on the ground. Refer to ”General Specifica-
tions” in this section.
The springs in the front suspension of engine family II are
stronger and the strut dampeners heavier than are the
springs and strut dampeners found in the front suspension
of engine family I.