en_4j2_2a.pdf part of Daewoo Nubira/Lacetti Service Manual - Daewoo Lacetti.part01.rar, Also known as: Chevrolet Nubira / Lacetti, Chevrolet Optra Optra5, Suzuki Forenza Reno Covers the 1.4L, 1.6L and 1.8L engine. Year 2004 text manual preview

Text preview for : en_4j2_2a.pdf part of Daewoo Nubira/Lacetti Also known as: Chevrolet Nubira / Lacetti, Chevrolet Optra Optra5, Suzuki Forenza Reno Covers the 1.4L, 1.6L and 1.8L engine. Year 2004

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SECTION : 2A

SUSPENSION DIAGNOSIS
TABLE OF CONTENTS
DIAGNOSIS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2A1 General Diagnosis . . . . . . . . . . . . . . . . . . . . . . . . . 2A1 Torque Steer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2A5 Tapered Roller Bearing . . . . . . . . . . . . . . . . . . . . . 2A6

DIAGNOSIS
GENERAL DIAGNOSIS
Problems in the steering, the suspension, the tires, and the wheels involve several systems. Consider all systems when diagnosing a complaint. Some problems, such as abnormal or excessive tire wear and scuffed tires, may be the result of hard driving. Always road test the vehicle first. If possible, do this road test with the customer. Proceed with the following preliminary checks. Correct any substandard conditions.

Preliminary Checks
Checks Inspect the tires for improper pressure and uneven wear. Inspect the joint from the steering column to the steering gear for loose connections or wear. Inspect the front and the rear suspension, the steering gear, and the linkage for loose or damaged parts. Action Inflate the tires to the proper pressure. Tighten the intermediate shaft pinch bolts. Replace the intermediate shaft as needed. Tighten the front and the rear suspension. Tighten the steering gear mounting bracket bolts. Tighten the coupling flange pinch bolts. Replace the front and the rear suspension as needed. Replace the steering gear as needed. Replace the intermediate shaft as needed. Perform a free runout test. Matchmount the tires. Balance the wheels. Replace the wheels. Replace the wheel bearings. Tighten the power steering pump serpentine belt. Repair any leaks. Perform a power steering gear test. Add power steering fluid.

Inspect for outofround tires. Inspect for outofbalance tires, bent wheels, and worn or loose wheel bearings. Check the power steering pump serpentine belt tension. Inspect the power steering system for leaks. Check the power steering fluid level.

Car Lead/Pull
Checks Inspect for mismatched or uneven tires. Inspect for a broken or a sagging spring. Inspect for a radial tire lateral force. Check the frontwheel alignment. Inspect for an offcenter steering gear. Inspect for frontbrake dragging. Replace the tires. Replace the spring. Check the wheel alignment. Switch the wheels. Replace the tires as needed. Align the front wheels. Reseat the pinion valve assembly. Replace the pinion valve assembly as needed. Adjust the front brakes. Action

2A 2ISUSPENSION DIAGNOSIS Abnormal or Excessive Tire Wear
Checks Check the frontwheel and the rearwheel alignment. Inspect for excessive toe on the front and the rear wheels. Inspect for a broken or a sagging spring. Inspect for outofbalance tires. Inspect for worn strut dampeners. Check for a failure to rotate tires. Check for an overloaded vehicle. Inspect for low tire inflation. Action Align the front and the rear wheels. Adjust the toe on the front and the rear wheels. Replace the spring. Balance the tires. Replace the strut dampeners. Rotate the tires. Replace the tires as needed. Maintain the proper load weight. Inflate the tires to the proper pressure.

Scuffed Tires
Checks Inspect for incorrect toe on the front and the rear wheels. Inspect for a twisted or a bent suspension arm. Action Adjust the toe on the front and the rear wheels. Replace the suspension arm.

Wheel Tramp
Checks Inspect for an outofbalance tire or wheel. Inspect for improper strut dampener action. Action Balance the tire or the wheel. Replace the strut dampeners.

Shimmy, Shake, or Vibration
Checks Inspect for an outofbalance tire or wheel. Inspect for excessive wheel hub runout. Inspect for excessive brake drum or brake rotor imbalance. Inspect for worn tie rod ends. Inspect for wheel trim imbalance. Inspect for a worn lower ball joint. Inspect for excessive wheel runout. Inspect for excessive loaded radial runout on the tire and wheel assembly. Action Balance the tire or the wheel. Measure the hub flange runout. Replace the hub as needed. Adjust the brakes. Replace the brake rotor or the brake drum as needed. Replace the outer tie rods. Balance the wheel. Replace the lower ball joint. Measure the wheel runout. Replace the wheel as needed. Matchmount the tire and wheel assembly.

Hard Steering
Checks Check the steering gear preload adjustment. Check the hydraulic system. Test the power steering system pressure with a gauge. Inspect for binding or catching in the steering gear. Inspect for a loose steering gear mounting. Action Perform a rack bearing preload adjustment. Replace the seals and the hoses as needed. Lubricate the steering gear. Repair or replace the steering gear as needed. Tighten the steering gear mounting bracket nuts.
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SUSPENSION DIAGNOSIS 2A 3 Too Much Play in Steering
Checks Inspect for worn or loose wheel bearings. Inspect for a loose steering gear mounting. Inspect the joint from the column to the steering gear for loose connections or wear. Check the steering gear preload adjustment. Action Tighten the drive axle nut. Replace the wheel bearings as needed. Tighten the steering gear mounting bracket nuts. Tighten the intermediate shaft pinch bolts. Replace the intermediate shaft as needed. Perform a rack bearing preload adjustment.

Poor Returnability
Checks Inspect for lack of lubrication of the ball joints and the tie rod ends. Inspect for binding in the ball joints. Inspect for binding in the steering column. Check the frontwheel alignment. Check the steering gear preload adjustment. Inspect for a sticking valve. Inspect for binding in the intermediate shaft on the steering gear. Action Replace the ball joints and the outer tie rods. Replace the ball joint. Lubricate the steering column. Replace the steering column as needed. Align the front wheels. Perform a rack bearing preload adjustment. Lubricate the pinion valve assembly. Replace the pinion valve assembly as needed. Replace the intermediate shaft.

Abnormal Noise, Front Suspension
Checks Inspect for a lack of lubrication of the ball joints and the tie rod ends. Inspect for damaged suspension components. Inspect for worn control arm bushings or tie rod ends. Inspect for a loose stabilizer shaft link. Inspect for loose wheel bolts. Inspect for loose suspension bolts or nuts. Inspect for worn strut dampeners or strut mountings. Inspect for an improperly positioned strut spring. Action Replace the ball joints and the outer tie rods. Replace the damaged suspension components. Replace the control arm bushings or the tie rods. Tighten the stabilizer shaft link. Tighten the wheel bolts. Tighten the suspension bolts or the nuts. Replace the strut dampeners. Tighten the strut mounting bolts. Adjust the strut spring to the proper position.

Wander or Poor Steering Ability
Checks Inspect for mismatched or uneven tires. Inspect for lack of lubrication of the ball joints and the tie rod ends. Inspect for worn strut dampeners. Inspect for a loose stabilizer shaft link. Inspect for a broken or a sagging spring.
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Action Replace the tires. Replace the ball joints and the outer tie rods. Replace the strut dampeners. Tighten the stabilizer shaft link. Replace the spring.

2A 4ISUSPENSION DIAGNOSIS
Checks Check the steering gear preload adjustment. Check the frontwheel and the rearwheel alignment. Action Perform a rack bearing preload adjustment. Align the front and the rear wheels.

Erratic Steering when Braking
Checks Inspect for worn or loose wheel bearings. Inspect for a broken or a sagging spring. Inspect for a leaking wheel cylinder or caliper. Inspect for warped rotors. Inspect for an incorrect or an uneven caster. Replace the spring. Replace the wheel cylinder or the caliper. Replace the rotors. If the caster is beyond specifications, check the frame and repair it as needed. Action Replace the wheel bearings.

Low or Uneven Trim Height
Checks Inspect for a broken or a sagging spring. Check for an overloaded vehicle. Inspect for an incorrect or weak spring. Replace the spring. Maintain the proper load weight. Replace the spring. Action

Ride Too Soft
Checks Inspect for worn strut dampeners. Inspect for a broken or a sagging spring. Replace the spring. Action Replace the strut dampeners.

Ride Too Harsh
Checks Inspect for incorrect strut dampeners. Inspect for an incorrect spring. Replace the spring. Action Replace the strut dampeners.

Body Leans or Sways in Corners
Checks Inspect for a loose stabilizer shaft link. Inspect for worn strut dampeners or strut mountings. Check for an overloaded vehicle. Inspect for a broken or a sagging spring. Action Tighten the stabilizer shaft link. Replace the strut dampeners. Tighten the strut assembly mounting bolts. Maintain the proper load weight. Replace the spring.

Suspension Bottoms
Checks Inspect for worn strut dampeners. Check for an overloaded vehicle. Inspect for a broken or a sagging spring. Action Replace the strut dampeners. Maintain the proper load weight. Replace the spring.

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SUSPENSION DIAGNOSIS 2A 5 Steering Wheel Kickback
Checks Inspect for air in the power steering system. Inspect for a loose steering gear mounting. Inspect the joint from the column to the steering gear for loose connections or wear. Inspect for loose tie rod ends. Inspect for loose or worn wheel bearings. Action Purge the power steering system of air. Tighten the steering gear mounting bracket nuts. Tighten the intermediate shaft pinch bolts. Replace the intermediate shaft as needed. Tighten the tie rod ends. Replace the outer tie rods as needed. Tighten the drive axle nut. Replace the wheel bearings as needed.

Steering Wheel Surges or Jerks
Checks Check the hydraulic system. Test the power steering system pressure with a gauge. Inspect for a sluggish steering gear valve. Inspect for a loose power steering pump serpentine belt. Action Replace the seals and the hoses as needed. Clean the pinion valve assembly. Replace the pinion valve assembly as needed. Adjust the power steering pump serpentine belt.

Cupped Tires
Checks Check the frontwheel and the rearwheel alignment. Inspect for worn strut dampeners. Inspect for worn or loose wheel bearings. Inspect for excessive tire or wheel runout. Inspect for a worn ball joint. Check the steering gear preload adjustment. Action Align the front and the rear wheels. Replace the strut dampeners. Tighten the drive axle nut. Replace the wheel bearings as needed. Matchmount the tires. Replace the tires as needed. Replace the wheels as needed. Replace the ball joint. Perform a rack bearing preload adjustment. 2. Note the inches of steering wheel deflection required to keep the vehicle straight during heavy acceleration. Compare this finding with similar cars.

TORQUE STEER
A degree of torque steer to the right may be experienced during the use of heavy throttle on some frontwheel drive cars with drive axles of unequal length. This torque steer to the right results from the right drive axle being longer than the left drive axle, which creates a difference in the drive axle angle. Cars with intermediate shaft assemblies have axles of almost equal length. A difference in the drive axle lengths results in more torque toein in the left front wheel. You will notice the torque toe in when the vehicle accelerates from a standing start or at lower speeds. 3.

Factors that may cause torque steer to be more apparent on a particular vehicle include: S Variations in the tire and wheel assemblies. This has the most significant effect on torque steer. A slightly smaller diameter on the right front tire will increase a right torque lead. Large differences in the right and the left front tire pressure. Looseness in the control arm bushings, the tie rod assemblies, or the steering gear mounting. This looseness permits a front wheel to pull forward and toein under a torque greater than the wheel on the opposite side. A loose suspension component may result in an opposite lead upon deceleration.

S S

Inspection Procedure
1. Place a small piece of tape at the top center of the steering wheel.

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2A 6ISUSPENSION DIAGNOSIS
S A high front trim height. This height would increase the drive axle angle and could cause wobble at speeds between 24 to 48 km/h (15 to 30 mph). Binding or a tight drive axle joint. A tight drive axle joint or a high front trim height may also cause a wobble at speeds between 24 to 48 km/h (15 to 30 mph). Incorrect, worn, or loose engine mounts causing adverse drive angles. 4. Mount a dial indicator set with a magnetic base to a control arm or any other stationary part of the vehicle. Push and pull the wheel hub by hand. If the wheel hub movement exceeds 0.05 mm (0.002 inch), replace the wheel bearing. Refer to Section 2D, Rear Suspension. Install the brake disc caliper and the brake rotor. Refer to Section 4E1, Rear Disc Brakes. Install the rear wheel. Refer to Section 2E, Tires and Wheels. Lower the vehicle.

S

5.

S

6. 7. 8.

Refer to "General Diagnosis" in this section for actions to remedy these problems. Conditions that may produce an effect similar to torque steer include: S S S S Incorrect front or rear alignment. Frame misalignment or defect. Front suspension damage. Incorrectly mounted rear crossmember.

TAPERED ROLLER BEARING
Perform the following test to check for looseness in the hub and bearing assembly on vehicles equipped with rear disc brakes: 1. 2. 3. Raise and suitably support the vehicle. Remove the rear wheel. Refer to Section 2E, Tires and Wheels. Remove the brake disc caliper and the brake rotor. Refer to Section 4E1, Rear Disc Brakes.

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