Suspension - General Diagnosis — Buick LeSabre VIII (2000-2005)

Scheme 1

Scheme 1: TRIM HEIGHT SPECIFICATIONS

DIAGNOSTIC STARTING POINT - SUSPENSION GENERAL DIAGNOSIS

Begin the system diagnosis by reviewing the system Description & Operation. Reviewing the Description and Operation information will help you determine the correct symptom diagnostic procedure when a malfunction exists. Reviewing the Description and Operation information, and the vehicle RPO, will also help you determine if the condition described by the customer is normal operation. See SYMPTOMS - SUSPENSION GENERAL DIAGNOSIS in order to identify the correct procedure for diagnosing the system and where the procedure is located.

SYMPTOMS - SUSPENSION GENERAL DIAGNOSIS

The following steps must be completed before using the symptom tables.

Determine whether the vehicle is equipped with an electrically assisted or active suspension system. Perform electrical diagnosis prior to beginning mechanical diagnosis.
Review the system description and operation in order to familiarize yourself with the system functions.

Visual/Physical Inspection

Inspect for aftermarket devices which could affect the operation of any of the suspension subsystems.
Inspect the easily accessible or visible system components for obvious damage or conditions which could cause the symptom.
Inspect for proper tire size and inflation pressure.

Symptom List

«RIDE DIAGNOSIS - TOO SOFT»(/buick/lesabre/viii-2000-2005/remont/suspension-front/#suspension-general-diagnosis__ride-diagnosis-too-soft)
«RIDE DIAGNOSIS - TOO HARD»(/buick/lesabre/viii-2000-2005/remont/suspension-front/#suspension-general-diagnosis__ride-diagnosis-too-hard)
«VEHICLE LEADS/PULLS»(/buick/lesabre/viii-2000-2005/remont/suspension-front/#suspension-general-diagnosis__vehicle-leadspulls)
«BODY LEANS OR SWAYS IN CORNERS»(/buick/lesabre/viii-2000-2005/remont/suspension-front/#suspension-general-diagnosis__body-leans-or-sways-in-corners)
«SUSPENSION BOTTOMS»(/buick/lesabre/viii-2000-2005/remont/suspension-front/#suspension-general-diagnosis__suspension-bottoms)
«TORQUE STEER»(/buick/lesabre/viii-2000-2005/remont/suspension-front/#suspension-general-diagnosis__torque-steer)
«MEMORY STEER»(/buick/lesabre/viii-2000-2005/remont/suspension-front/#suspension-general-diagnosis__memory-steer)
«POOR DIRECTIONAL STABILITY»(/buick/lesabre/viii-2000-2005/remont/suspension-front/#suspension-general-diagnosis__poor-directional-stability)
«TIRE HOP OR POOR HANDLING»(/buick/lesabre/viii-2000-2005/remont/suspension-front/#suspension-general-diagnosis__tire-hop-or-poor-handling)
«NOISE DIAGNOSIS - FRONT SUSPENSION»(/buick/lesabre/viii-2000-2005/remont/suspension-front/#suspension-general-diagnosis__noise-diagnosis-front-suspension)
«NOISE DIAGNOSIS - REAR SUSPENSION»(/buick/lesabre/viii-2000-2005/remont/suspension-front/#suspension-general-diagnosis__noise-diagnosis-rear-suspension)
«BALL JOINT INSPECTION»(/buick/lesabre/viii-2000-2005/remont/suspension-front/#suspension-general-diagnosis__ball-joint-inspection)
«STRUTS OR SHOCK ABSORBERS ON-VEHICLE TESTING»(/buick/lesabre/viii-2000-2005/remont/suspension-front/#suspension-general-diagnosis__struts-or-shock-absorbers-on-vehicle-testing)
«WHEEL BEARINGS DIAGNOSIS»(/buick/lesabre/viii-2000-2005/remont/suspension-front/#suspension-general-diagnosis__wheel-bearings-diagnosis)
«TRIM HEIGHT INSPECTION PROCEDURE»(/buick/lesabre/viii-2000-2005/remont/suspension-front/#suspension-general-diagnosis)
«RADIAL TIRE LEAD/PULL CORRECTION»(/buick/lesabre/viii-2000-2005/remont/suspension-front/#suspension-general-diagnosis__radial-tire-leadpull-correction)

RIDE DIAGNOSIS - TOO SOFT

Did you review the General Description and perform the necessary inspections? If yes, go to next step. If no, go to «SYMPTOMS - SUSPENSION GENERAL DIAGNOSIS»(/buick/lesabre/viii-2000-2005/remont/suspension-front/#suspension-general-diagnosis__symptoms-suspension-general-diagnosis) .
Verify that the ride is too soft. Does the vehicle ride normally? Id yes, system is okay. If no, go to next step.
Inspect the tires for the proper inflation pressure. Is the tire inflation pressure correct? If yes, go to step 5 . If no, go to next step.
Inflate the tires to the correct pressure. After correcting air pressure, go to next step.
Inspect the vehicle trim height. Refer to «TRIM HEIGHT INSPECTION PROCEDURE»(/buick/lesabre/viii-2000-2005/remont/suspension-front/#suspension-general-diagnosis) . Repair as necessary. Did you complete the inspection/repair? If yes, go to next step.
Inspect the springs, struts or shock absorbers for wear or damage. Are any of the components the worn or damaged? If yes, go to next step. If no, go to next step.
Replace all of the worn or damaged components. For strut component replacement, refer to Strut, Strut Component and/or Spring Replacement in Front Suspension, for shock absorber replacement, refer to Shock Absorber Replacement in Rear Suspension or for spring replacement, refer to Coil Spring Replacement in Rear Suspension. After repairs, system is okay.
Inspect the automatic level control system. Refer to Diagnostic Starting Point - Automatic Level Control in Automatic Level Control. Repair as necessary. After repairs, go to next step.
Drive the vehicle in order to verify the repair. Did you correct the condition? If yes, system is okay. If no, go to step 2 .

RIDE DIAGNOSIS - TOO HARD

Did you review the General Description and perform the necessary inspections? If yes, go to next step. If no, go to «SYMPTOMS - SUSPENSION GENERAL DIAGNOSIS»(/buick/lesabre/viii-2000-2005/remont/suspension-front/#suspension-general-diagnosis__symptoms-suspension-general-diagnosis) .
Verify that the ride is too hard. Does the vehicle ride normally? If yes, system is okay. If no, go to next step.
Inspect the tires for the proper inflation pressure. Is the tire inflation pressure correct? If yes, go to step 6 . If no, go to next step.
Inflate the tires to the correct pressure. After correcting tire pressure, go to next step.
Inspect the Springs, Struts, and Shock Absorbers for wear or damage. Refer to «STRUTS OR SHOCK ABSORBERS ON-VEHICLE TESTING»(/buick/lesabre/viii-2000-2005/remont/suspension-front/#suspension-general-diagnosis__struts-or-shock-absorbers-on-vehicle-testing) . Are any of the components the worn or damaged? If yes, go to next step. If no, go to step 7 .
Replace all of the worn or damaged components. For strut component replacement, refer to Strut, Strut Component and/or Spring Replacement in Front Suspension, for shock absorber replacement, refer to Shock Absorber Replacement in Rear Suspension or for spring replacement, refer to Coil Spring Replacement in Rear Suspension. After repairs, go to next step.
Inspect the automatic level control system. Refer to Diagnostic Starting Point - Automatic Level Control in Automatic Level Control. Repair as necessary. After repairs, go to next step.
Operate the system in order to verify the repair. Did you correct the condition? If yes, system is okay. If no, go to step 3 .

VEHICLE LEADS/PULLS

DEFINITION: Lead/pull is the deviation of the vehicle from a straight path on a level road with no pressure on the steering wheel. Use the lead/pull correction table in order to verify that improper wheel alignment or worn components are not mistaken for tire lead.

Did you review the General Description and perform the necessary inspections? If yes, go to next step. If no, go to «SYMPTOMS - SUSPENSION GENERAL DIAGNOSIS»(/buick/lesabre/viii-2000-2005/remont/suspension-front/#suspension-general-diagnosis__symptoms-suspension-general-diagnosis) .
Road test the vehicle in order to verify the complaint. Select a smooth level surface to perform the test. Does the vehicle operate normally? If yes, system is okay. If no, go to next step.
Inspect the tire/wheel assemblies for: Correct tire pressure. Correct tire size. Did you find and correct the condition? If yes, go to next step. If no, go to step 5 .
Repair/replace the tire/wheel assemblies as necessary. After repair is complete, go to step 15 .
Inspect the front/rear suspensions for the following conditions: Vehicle trim height. See «TRIM HEIGHT INSPECTION PROCEDURE»(/buick/lesabre/viii-2000-2005/remont/suspension-front/#suspension-general-diagnosis) Excessively worn, loose, or damaged components. Excessive wheel bearing play. Refer to «WHEEL BEARINGS DIAGNOSIS»(/buick/lesabre/viii-2000-2005/remont/suspension-front/#suspension-general-diagnosis__wheel-bearings-diagnosis) . Did you find and correct the condition? If yes, go to next step. If no, go to step 7 .
Repair/replace components as necessary. Tighten components to specifications. Replace the wheel bearings. After repairs, go to step 13 .
Inspect the brake system for brake drag. Refer to «BRAKES DRAG»(/buick/lesabre/viii-2000-2005/remont/mechanical-hydraulic/#disc-brakes__brakes-drag) . Do any of the above conditions apply? If yes, go to next step. If no, go to step 9 .
Repair/replace components as necessary. After repair is complete, go to step 15 .
Inspect the steering gear valve for an unbalance. If this is the cause, steering effort will be very light in the direction of the lead and effort will be heavy in the opposite direction with the vehicle parked on a smooth level surface. Does the above condition apply? If yes, go to next step. If no, go to step 11 .
Replace the steering gear. Refer to Power Steering Gear Replacement in Power Steering System. After repairs, go to step 15 .
Inspect the wheel alignment. Refer to Measuring Wheel Alignment in Wheel Alignment. Is the wheel alignment in specifications? If yes, go to step 13 . If no, go to next step.
Adjust alignment to specifications. Refer to Measuring Wheel Alignment in Wheel Alignment. After repairs, go to step 15 .
Cross-switch the front tire/wheel assemblies. Road test the vehicle on a smooth level surface. Does the vehicle still lead/pull? If yes, go to next step. If no, system is okay.
Does the vehicle lead/pull in the opposite direction? If yes, see «RADIAL TIRE LEAD/PULL CORRECTION»(/buick/lesabre/viii-2000-2005/remont/suspension-front/#suspension-general-diagnosis__radial-tire-leadpull-correction) . If no, go to next step.
Operate the vehicle in order to verify the repair. Did you correct the condition? If yes, system is okay. If no, go to step 3 .

BODY LEANS OR SWAYS IN CORNERS

Check for the following conditions

Did you review the General Description and perform the necessary inspections? If yes, go to next step. If no, go to «SYMPTOMS - SUSPENSION GENERAL DIAGNOSIS»(/buick/lesabre/viii-2000-2005/remont/suspension-front/#suspension-general-diagnosis__symptoms-suspension-general-diagnosis) .
Verify the vehicle leans or sways in corners. Does the vehicle operate normally? If yes, system is okay. If no, go to next step.
Inspect the front coil springs and rear coil springs for wear or damage. Are the components worn or damaged? If yes, go to step 5 . If no, go to next step.
Inspect the stabilizer shaft link for wear or damage. Is the stabilizer shaft link worn or damaged? If yes, go to step 6 . If no, go to step 2 .
Replace the springs. Refer to Strut, Strut Component and/or Spring Replacement in Front Suspension or Strut Disassemble/Assemble Repair in Rear Suspension. After repairs, go to step 7 .
Replace the stabilizer shaft link. Refer to the appropriate procedure: Stabilizer Shaft Link Replacement in Front Suspension or Stabilizer Shaft Link Replacement in Rear Suspension. After repairs, go to next step.
Operate the vehicle in order to verify the repair. Did you correct the condition? If yes, system is okay. If no, go to step 3 .

SUSPENSION BOTTOMS

DEFINITION: A loud bang or thump that can usually be felt and/or heard when the vehicle is driven over bumps. This condition is commonly noticed when the vehicle trim height is too low.

Did you review the General Description and perform the necessary inspections? If yes, go to next step. If no, go to «SYMPTOMS - SUSPENSION GENERAL DIAGNOSIS»(/buick/lesabre/viii-2000-2005/remont/suspension-front/#suspension-general-diagnosis__symptoms-suspension-general-diagnosis) .
Verify that the suspension bottoms. Does the vehicle operate normally? If yes, system is okay. If no, go to next step.
Check for vehicle overloading. Is the vehicle overloaded? If yes, go to step 6 . If no, go to next step.
Inspect the vehicle trim height. Refer to «TRIM HEIGHT INSPECTION PROCEDURE»(/buick/lesabre/viii-2000-2005/remont/suspension-front/#suspension-general-diagnosis) . Is the vehicle trim height incorrect? If yes, go to step 7 . If no, go to next step.
Inspect the struts and shock absorbers. Refer to «STRUTS OR SHOCK ABSORBERS ON-VEHICLE TESTING»(/buick/lesabre/viii-2000-2005/remont/suspension-front/#suspension-general-diagnosis__struts-or-shock-absorbers-on-vehicle-testing) . Are the components in need of replacement? If yes, go to step 8 . If no, go to step 9 .
Remove the excess weight from the vehicle. Did you remove the excess weight from the vehicle? If yes, go to step 9 .
Correct the vehicle trim height. Refer to «TRIM HEIGHT INSPECTION PROCEDURE»(/buick/lesabre/viii-2000-2005/remont/suspension-front/#suspension-general-diagnosis) . After repairs, go to step 9 .
Replace the components as necessary. After repairs, go to next step.
Operate the vehicle in order to verify the repair. Did you correct the condition? If yes, system is okay. If no, go to step 3 .

TORQUE STEER

DEFINITION: On a dry, smooth, flat road, the vehicle has a left or right steering force that is eliminated when the transmission is shifted into Neutral. The level of the steering force is usually (but not always) dependent on the amount of torque which is applied by the engine. Torque steer at constant highway speed is frequently mistaken for lead/pull.

Did you review the General Description and perform the necessary inspections? If yes, go to next step. If no, go to «SYMPTOMS - SUSPENSION GENERAL DIAGNOSIS»(/buick/lesabre/viii-2000-2005/remont/suspension-front/#suspension-general-diagnosis__symptoms-suspension-general-diagnosis) .
Drive the vehicle on a straight, smooth, flat road at 64-97 km/h (40-60 mph). Remove your foot from the accelerator. Shift the transmission into Neutral in order to allow the vehicle to coast. Momentarily release the steering wheel and note any change in the direction of the vehicle. Repeat this test with the vehicle traveling in the opposite direction in order to eliminate crosswind effects. Lead/pull caused by unlevel roads and crosswinds are considered normal. Does the vehicle direction change when the steering wheel is momentarily released? If yes, go to «RADIAL TIRE LEAD/PULL CORRECTION»(/buick/lesabre/viii-2000-2005/remont/suspension-front/#suspension-general-diagnosis__radial-tire-leadpull-correction) . If no, go to next step.
Drive the vehicle on a straight, smooth, flat road. Shift the transmission into Drive. Press the accelerator and momentarily release the steering wheel. Repeat this test with the vehicle traveling in the opposite direction in order to eliminate crosswind effects. Lead/pull caused by unlevel roads and crosswinds are considered normal. Does the vehicle exhibit torque steer when the accelerator is pressed? If yes, go to next step. If no, system is okay.
Inspect the front suspension for worn or damaged components. Repair as necessary. After repairs, go to next step.
Inspect the vehicle trim height. Refer to «TRIM HEIGHT INSPECTION PROCEDURE»(/buick/lesabre/viii-2000-2005/remont/suspension-front/#suspension-general-diagnosis) . Repair as necessary. Road test the vehicle in order to verify the customer complaint. Does the vehicle still exhibit torque steer? If yes, go to next step. If no, system is okay.
Inspect for worn or damaged powertrain mounts. Replace as necessary. Has the inspection/repair been performed? If yes, go to next step.
Operate the vehicle in order to verify the repair. Did you correct the condition? If yes, system is okay. If no, go to step 3 .

MEMORY STEER

DEFINITION: The steering wheel does not return to center after completing a turn.

Did you review the General Description and perform the necessary inspections? If yes, go to next step. If no, go to «SYMPTOMS - SUSPENSION GENERAL DIAGNOSIS»(/buick/lesabre/viii-2000-2005/remont/suspension-front/#suspension-general-diagnosis__symptoms-suspension-general-diagnosis) .
Verify that memory steer is present. Does the system operate normally? If yes, system is okay. If no, go to next step.
Ensure that all of the tires are inflated to the correct pressure. Has the inspection/adjustment been performed? If yes, go to next step.
Lubricate the tie rod ends and the ball joints if applicable. Inspect the suspension system for worn or damaged components. Repair as necessary. Road test the vehicle in order to verify the customer complaint. Does the vehicle still exhibit memory steer? If yes, go to next step. If no, system is okay.
Check for proper wheel alignment. Refer to Measuring Wheel Alignment in Wheel Alignment. Adjust as necessary. Road test the vehicle in order to verify the customer complaint. Does the vehicle still exhibit memory steer? If yes, go to next step. If no, system is okay.
Raise and support the vehicle. Disconnect both of the outer tie rod ends from the steering knuckles. Refer to Tie Rod End Replacement - Outer in Power Steering System. Use your hands in order to move the tie rod ends. Are either of the tie rod ends abnormally difficult to move? If yes, go to next step. If no, go to step 8 .
Replace the outer tie rod end(s) as necessary. Refer to Tie Rod End Replacement - Outer in Power Steering System. Road test the vehicle in order to verify the customer complaint. Does the vehicle still exhibit memory steer? If yes, go to next step. If no, system is okay.
Inspect for binding strut bearings and lower ball joints. Use your hands to push and pull the front of the wheels inboard and outboard. Are either of the struts abnormally difficult to move? If yes, go to next step. If no, go to step 13 .
Remove the tire/wheel. Disconnect the strut from the steering knuckle. Refer to Strut Assembly Replacement in Front Suspension. Use your hands to rotate the strut. Is the strut abnormally difficult to rotate? If yes, go to next step. If no, go to step 11 .
Replace the strut bearing. Refer to Strut, Strut Component and/or Spring Replacement in Front Suspension. Road test the vehicle in order to verify the customer complaint. Does the vehicle still exhibit memory steer? If yes, go to step 13 . If no, system is okay.
Use your hands in order to rotate the steering knuckle/ball joint. Is the steering knuckle/ball joint abnormally difficult to rotate? If yes, go to next step. If no, go to step 13 .
Replace the lower ball joint. Refer to Lower Ball Joint Replacement in Front Suspension. Road test the vehicle in order to verify the customer complaint. Does the vehicle still exhibit memory steer? If yes, go to next step. If no, system is okay.
Raise and support the vehicle. Rotate the steering wheel ONE revolution in either direction. Rotate the steering wheel back to the original position. Was the steering wheel abnormally difficult to rotate in either direction? If yes, go to next step. If no, go to step 1 .
Disconnect the intermediate shaft. Refer to Intermediate Steering Shaft Replacement in Steering Wheel and Column - Tilt. Note the position of the steering wheel and rotate the steering wheel ONE revolution in either direction. Rotate the steering wheel back to the original position as previously noted. Was the steering wheel abnormally difficult to rotate in either direction? If yes, go to step 16 . If no, go to next step.
Repair the steering gear as necessary. Refer to Power Steering Gear Replacement in Power Steering System. Road test the vehicle in order to verify the customer complaint. Does the vehicle still exhibit memory steer? If yes, go to step 1 . If no, system is okay.
Repair the steering column as necessary. After repairs, go to next step.
Operate the vehicle in order to verify the repair. Did you correct the condition? If yes, system is okay. If no, go to step 3 3.

POOR DIRECTIONAL STABILITY

DEFINITION: Driver is unable to maintain consistent, predictable vehicle driving control in any direction.

Did you review the General Description and perform the necessary inspections? If yes, go to next step. If no, go to «SYMPTOMS - SUSPENSION GENERAL DIAGNOSIS»(/buick/lesabre/viii-2000-2005/remont/suspension-front/#suspension-general-diagnosis__symptoms-suspension-general-diagnosis) .
Verify that the directional stability is poor. Does the system operate normally? If yes, system is okay. If no, go to next step.
Ensure that the tires are all the same size, make, and adequate tread depth. Repair as necessary. Ensure that all of the tires are inflated to the correct pressure. Does the vehicle still exhibit poor directional stability? If yes, go to next step. If no, system is okay.
Inspect the stabilizer shaft, links, and insulators for wear or damage. Repair as necessary. Refer to Stabilizer Shaft Link Replacement and Stabilizer Shaft Insulator Replacement in Front Suspension. Does the vehicle still exhibit poor directional stability? If yes, go to next step. If no, system is okay.
Inspect the lower control arms, ball joints and tie rods for wear or damage. Repair as necessary. Refer to Lower Control Arm Replacement and Lower Ball Joint Replacement in Front Suspension. Refer to Tie Rod End Replacement - Outer in Power Steering System. Does the vehicle still exhibit poor directional stability? If yes, go to next step. If no, system is okay.
Inspect the wheel bearings/hubs for looseness or excessive lateral runout. Refer to «WHEEL BEARINGS DIAGNOSIS»(/buick/lesabre/viii-2000-2005/remont/suspension-front/#suspension-general-diagnosis__wheel-bearings-diagnosis) . Does the vehicle still exhibit poor directional stability? If yes, go to next step. If no, system is okay.
Inspect the vehicle trim height. Refer to «TRIM HEIGHT INSPECTION PROCEDURE»(/buick/lesabre/viii-2000-2005/remont/suspension-front/#suspension-general-diagnosis) . Repair as necessary. Does the vehicle still exhibit poor directional stability? If yes, go to next step. If no, system is okay.
Inspect and adjust the wheel alignment as necessary. Refer to Measuring Wheel Alignment in Wheel Alignment. Does the vehicle still exhibit poor directional stability? If yes, go to next step. If no, system is okay.
Inspect the steering gear and steering column for looseness. Repair as necessary. After repairs, go to next step.
Operate the vehicle in order to verify the repair. Did you correct the condition? If yes, system is okay. If no, go to step 3 .

TIRE HOP OR POOR HANDLING

DEFINITION: The tire/wheel bounce with a frequency directly related to the vehicle speed.

Did you review the General Description and perform the necessary inspections? If yes, go to next step. If no, go to «SYMPTOMS - SUSPENSION GENERAL DIAGNOSIS»(/buick/lesabre/viii-2000-2005/remont/suspension-front/#suspension-general-diagnosis__symptoms-suspension-general-diagnosis) .
Verify that the tires hop or that the vehicle handles poorly. Does the vehicle handle normally? If yes, system is okay. If no, go to next step.
Inspect the tires for uneven wear or damage. Are the tires worn or damaged? If yes, go to step 7 . If no, go to next step.
Inspect the tires and wheels for missing wheel weights. Are the wheel weights missing? If yes, go to step 8 . If no, go to next step.
Inspect the tires and wheels for excessive runout. Does the tire and wheel have excessive runout? If yes, go to step 7 . If no, go to next step.
Inspect the shock absorbers/struts for wear or damage. Are the shock absorbers/struts worn or damaged? If yes, go to step 9 . If no, go to step 10 .
Replace the tire/wheel if necessary. After repairs, go to step 10 .
Balance the tire and wheel assembly. After repairs, go to step 10 .
Replace the struts. Refer to Strut, Strut Component and/or Spring Replacement in Front Suspension or Strut Assembly Replacement in Rear Suspension. After repairs, go to next step.
Operate the system in order to verify the repair. Did you correct the condition? If yes, system is okay. If no, go to step 3 .

NOISE DIAGNOSIS - FRONT SUSPENSION

DEFINITION: Any noise emitted from the front of the vehicle that is induced by vehicle speed or driving terrain as related to the front suspension.

Did you review the General Description and perform the necessary inspections? If yes, go to next step. If no, go to «SYMPTOMS - SUSPENSION GENERAL DIAGNOSIS»(/buick/lesabre/viii-2000-2005/remont/suspension-front/#suspension-general-diagnosis__symptoms-suspension-general-diagnosis) .
Attempt to duplicate the noise. Road test the vehicle. Is the front suspension noisy? If yes, go to next step. If no, system is okay.
Shift the transmission into Park. Turn the ignition off. Bounce the front of the vehicle in order to duplicate the noise. Is the noise heard? If yes, go to next step. If no, go to step 5 .
Bounce the front of the vehicle. Use a stethoscope in order to locate the source of the noise. Repair or replace the suspect component(s) as necessary. After repairs, go to step 25 .
Raise and support the vehicle. Inspect all of the front suspension components for any damage. Are any components damaged? If yes, go to next step. If no, go to step 7 .
Repair any damaged components. After repairs, go to step 25
Inspect the tires for proper inflation. Correct the tire inflation pressure as necessary. Inspect the tires for unusual wear. Does either tire exhibit unusual tread wear? If yes, go to next step. If no, go to step 10 .
Rotate the tires. Road test the vehicle. Is the noise now emitted from the rear of the vehicle? If yes, go to next step. If no, go to step 10 .
Replace the tire(s) that are causing the noise. After repairs, go to step 25 .
Ensure that the ball joints and steering linkage are lubricated (if applicable). Lubricate/replace as necessary. Did you service any components? If yes, go to step 25 . If no, go to next step.
Ensure that all of the wheel nuts are tightened to the correct specification. Tighten as necessary. Did you tighten any wheel nuts? If yes, go to step 25 . If no, go to next step.
Use your hands in order to push and pull the strut. Is the strut loose? If yes, go to next step. If no, go to step 15 .
Inspect the strut fasteners for the correct fastener tightening specification. Tighten as necessary. Use your hand to push and pull the strut. Is the strut loose? If yes, go to step 15 . If no, go to step 25 .
Replace the loose or worn strut components. Refer to Strut, Strut Component and/or Spring Replacement in Front Suspension. After repairs, go to step 25 .
Use your hands in order to push and pull on the stabilizer shaft. Is the stabilizer shaft loose? If yes, go to next step. If no, go to step 20 .
Inspect all of the stabilizer shaft fasteners. Tighten as necessary. Use your hands in order to push and pull on the stabilizer shaft. Is the stabilizer shaft loose? If yes, go to step 19 . If no, go to step 25 .
Observe the location of the stabilizer shaft looseness. Is the looseness observed at the stabilizer shaft link(s)? If yes, go to next step. If no, go to step 20 .
Replace the stabilizer shaft link(s). Refer to Stabilizer Shaft Link Replacement in Front Suspension. After repairs, go to step 25 .
Replace the stabilizer shaft insulator(s) and/or bracket(s). Refer to Stabilizer Shaft Insulator Replacement in Front Suspension. After repairs, go to step 25 .
Inspect the control arms for looseness or movement. Is any looseness or movement observed? If yes, go to next step. If no, go to step 23 .
Inspect the control arm fasteners for the correct fastener tightening specification. Tighten as necessary. Inspect the control arm for looseness. Is the control arm loose? If yes, go to next step. If no, go to step 25 .
Replace any worn or loose control arm bushings. Refer to Lower Control Arm Bushings Replacement in Front Suspension. After repairs, go to step 25 .
Start the engine with the drive wheels off of the ground. Shift the transmission into Drive. Increase the drive wheel speed until the noise is at the most audible level. Use a stethoscope in order to locate the source of the noise. Does either wheel bearing exhibit noise? If yes, go to next step. If no, go to step 8 .
Replace the wheel bearing(s). Refer to Wheel Bearing/Hub Replacement - Front in Front Suspension. After repairs, go to next step.
Operate the vehicle in order to verify the repair. Did you correct the condition? If yes, system is okay. If no, go to step 3 .

NOISE DIAGNOSIS - REAR SUSPENSION

DEFINITION: Any noise emitted from the rear of the vehicle that is induced by vehicle speed or driving terrain as related to the rear suspension.

Did you review the General Description and perform the necessary inspections? If yes, go to next step. If no, go to «SYMPTOMS - SUSPENSION GENERAL DIAGNOSIS»(/buick/lesabre/viii-2000-2005/remont/suspension-front/#suspension-general-diagnosis__symptoms-suspension-general-diagnosis) .
Verify that the rear suspension is noisy. Is the rear suspension noisy? If yes, go to next step. If no, system is okay.
Shift the transmission into Park. Turn the ignition off. Bounce the rear of the vehicle in order to duplicate the noise. Is the complaint noise heard? If yes, go to next step. If no, go to step 5 .
Bounce the rear of the vehicle. Use a stethoscope in order to locate the source of the noise. Repair or replace the suspect component(s) as necessary. After repairs, go to step 23 .
Raise and support the vehicle. Inspect all of the rear suspension components for any damage. Are any components damaged? If yes, go to next step. If no, go to step 7 .
Repair or replace any damaged components. After repairs, go to step 23 .
Inspect the tires for proper inflation. Correct the tire inflation pressure as necessary. Inspect the tires for unusual wear. Does either tire exhibit unusual tread wear? If yes, go to next step. If no, go to step 10 .
Rotate the tires. Road test the vehicle. Is the noise now emitted from the front of the vehicle? If yes, go to next step. If no, go to step 10 .
Replace the tire(s) that are causing the noise. After repairs, go to step 23 .
Ensure that the park brake cable and the spare tire are secured properly. Did you service any components? If yes, go to step 23 . If no, go to next step.
Ensure that all of the wheel nuts are tightened to the correct specification. Tighten as necessary. Did you tighten any of the wheel nuts? If yes, go to step 23 . If no, go to next step.
Raise and support the vehicle. Use your hand to push and pull the shock absorbers. Is either shock absorber loose? If yes, go to next step. If no, go to step 15 .
Inspect the strut fasteners for the correct fastener tightening specification. Tighten as necessary. Use your hands in order to push and pull the strut. Is the strut loose? If yes, go to step 15 . If no, go to step 23 .
Replace the loose or worn strut. Refer to the following: Strut, Strut Component and/or Spring Replacement in Front Suspension or Strut Assembly Replacement in Rear Suspension. After repairs, go to step 23 .
Use your hands in order to push and pull on the rear axle tie rod. Is the rear axle tie rod loose? If yes, go to next step. If no, go to step 18 .
Inspect the rear axle tie rod fasteners. Tighten as necessary. Use your hands in order to push and pull on the rear axle tie rod. Is the rear axle tie rod loose? If yes, go to next step. If no, go to step 23 .
Replace the rear axle tie rod as necessary. After repairs, go to step 23 .
Use your hands in order to push and pull on the rear axle trailing arm. Is either rear axle trailing arm loose? If yes, go to next step. If no, go to step 21 .
Inspect the rear axle trailing arm fasteners for the correct fastener tightening specification. Tighten as necessary. Use your hands in order to push and pull on the rear axle trailing arm. Is either rear axle trailing arm loose? If yes, go to next step. If no, go to step 23 .
Replace any worn or loose rear axle trailing arm bushings. After repairs, go to step 23 .
Use an on-vehicle wheel balancer in order to spin the rear wheels. Increase the wheel speed until the noise is at the most audible level. Use a stethoscope in order to locate the source of the noise. Does either wheel bearing exhibit excessive noise? If yes, go to next step. If no, go to step 8 .
Replace the wheel bearing(s). Refer to Wheel Bearing/Hub Replacement - Rear in Rear Suspension. After repairs, go to step 1 .
Operate the vehicle in order to verify the repair. Does the system operate normally? If yes, system is okay. If no, go to step 3 .

BALL JOINT INSPECTION

Note. Tools Required: J 8001 Dial Indicator

Note. The vehicle must rest on a level surface. The vehicle must be stable. Do not rock the vehicle on the jack stands.

Scheme 2

Scheme 2: BALL JOINT INSPECTION

Scheme 3

Raise and support the vehicle with safety stands.
Support the lower control arm with a jack stand, as far outboard as possible, near the lower ball joint.
Wipe the ball joint clean. Check the seals for cuts or tears.
Check the wheel bearing for looseness. Refer to «WHEEL BEARINGS DIAGNOSIS»(/buick/lesabre/viii-2000-2005/remont/suspension-front/#suspension-general-diagnosis__wheel-bearings-diagnosis) .
Check the ball joint for horizontal looseness. Position the J 8001 against the lowest outboard point on the wheel rim. Rock the wheel in and out while reading the J 8001. This shows horizontal looseness in the lower ball joint. The J 8001 reading should be no more than 3.18 mm (0.125 in). If the reading is too high, check the lower ball joint for vertical looseness.
Check the lower ball joint for wear and for vertical looseness using the following procedure: Inspect by sight the lower ball joint for wear. The position of the housing into which the grease fitting is threaded indicates wear. This round housing projects 1.27 mm (0.050 in) beyond the surface of the lower ball joint cover on a new ball joint. Under normal wear, the surface of the lower ball joint housing retreats inward very slowly. First observe, then scrape a scale, a screwdriver, or a fingernail across the cover. If the round housing is flush with or inside of the cover surface, replace the lower control arm. Refer to Lower Control Arm Replacement in Front Suspension. Pry between the lower control arm and the steering knuckle while reading the J 8001. This shows vertical looseness in the ball joint. The lower ball joint is not preloaded and may show some looseness. If the J 8001 reading is more than 3.18 mm (0.125 in), replace the lower control arm. Refer to Lower Control Arm Replacement in Front Suspension.

STRUTS OR SHOCK ABSORBERS ON-VEHICLE TESTING

Did you review the General Description and perform the necessary inspections? If yes, go to next step. If no, go to «SYMPTOMS - SUSPENSION GENERAL DIAGNOSIS»(/buick/lesabre/viii-2000-2005/remont/suspension-front/#suspension-general-diagnosis__symptoms-suspension-general-diagnosis) .
Verify that the malfunction is present. Does the vehicle operate normally? If yes, system is okay. If no, go to next step.
Inspect each strut or shock absorber for external fluid leakage. Is the strut or shock absorber leaking? If yes, so to step 8 . If no, go to next step.
Inspect the vehicle trim height. Refer to «TRIM HEIGHT INSPECTION PROCEDURE»(/buick/lesabre/viii-2000-2005/remont/suspension-front/#suspension-general-diagnosis) . Is the vehicle trim height correct? If yes, go to next step. If no, go to step 6 .
Use your hands in order to lift up and push down each corner of the vehicle 3 times. Remove your hands from the vehicle. Does the vehicle stop bouncing after 2 cycles? If yes, go to step 8 . If no, go to step 7 .
Replace the front spring or the rear spring. Refer to Strut, Strut Component and/or Spring Replacement in Front Suspension. Refer to Coil Spring Replacement in Rear Suspension. After repairs, go to step 8 .
Replace the strut or shock absorber. Refer to Strut, Strut Component and/or Spring Replacement in Front Suspension. Refer to Shock Absorber Replacement in Rear Suspension. After repairs, go to next step.
Operate the vehicle in order to verify the repair. Did you correct the condition? If yes, system is okay. If no, go to step 3 .

WHEEL BEARINGS DIAGNOSIS

Note. Tools Required: (J-8001) Dial Indicator Set.

Raise and support the vehicle.
Mount and secure the J 8001 to a stand.
Ensure that the J 8001 contacts the vertical surface of the wheel as close as possible to the top wheel stud. (Scheme 4)
Push and pull on the TOP of the tire.
Inspect the total movement indicated by the J 8001.
If the measurement exceeds 0.127 mm (0.005 in), replace the wheel bearing/hub. Refer to Wheel Bearing/Hub Replacement - Front in Front Suspension.

Trim Height Measurements

Trim height is a predetermined measurement relating to vehicle ride height. Incorrect trim heights can cause bottoming out over bumps, damage to the suspension components and symptoms similar to wheel alignment problems. Check the trim heights when diagnosing suspension concerns and before checking the wheel alignment.

Perform the following before measuring the trim heights

Set the tire pressures to the pressure shown on the certification label.
Check the fuel level. Add additional weight if necessary to simulate a full tank.
Make sure the rear compartment is empty except for the spare tire.
Make sure the vehicle is on a level surface, such as an alignment rack.
Close the doors.
Close the hood.
All dimensions are measured vertical to the ground. Trim heights should be within 13 mm (0.5 in) to be considered correct. See «TRIM HEIGHT SPECIFICATIONS»(/buick/lesabre/viii-2000-2005/remont/suspension-front/#suspension-general-diagnosis) .

Z Height Measurement

The Z height dimension measurement determines the proper ride height for the front end of the vehicle. There is no adjustment procedure. Repair may require replacement of suspension components.

Scheme 4

Scheme 4: Z Height Measurement

Lift the front bumper of the vehicle up about 38 mm (1.5 in).
Gently remove your hands. Let the vehicle settle.
Repeat this operation for a total of 3 times.
Measure from the pivot bolt center line down to the lower corner of the lower ball joint in order to obtain the Z height measurement.
Push the front bumper of the vehicle down about 38 mm (1.5 in).
Gently remove your hands.
Allow the vehicle to settle into position.
Repeat the jouncing operation 2 more times for a total of 3 times.
Measure the Z dimension.
The true Z height dimension number is the average of the high and the low measurements. Refer to «TRIM HEIGHT SPECIFICATIONS»(/buick/lesabre/viii-2000-2005/remont/suspension-front/#suspension-general-diagnosis) .

D Height Measurement

The D height dimension measurement determines the proper rear end ride height. There is no adjustment procedure. Repair may require replacement of suspension components.

Scheme 5

Scheme 5: D Height Measurement

With the vehicle on a flat surface, lift upward on the rear bumper 38 mm (1.5 in).
Gently remove your hands. Allow the vehicle to settle into position.
Repeat the jouncing operation 2 more times for a total of 3 times.
The D height is measured from a point 30 mm (1.1 in) outboard of the rear brake hose bracket bolt centerline to the bolt centerline of the trailing arm to the knuckle attachment.
Push the rear bumper downward to 38 mm (1.5 in).
Gently remove your hands. Allow the vehicle to settle into position.
Repeat the jouncing operation 2 more times for a total of 3 times.
Measure the D height dimension.
The true D height dimension number is the average of the high and the low measurements. Refer to «TRIM HEIGHT SPECIFICATIONS»(/buick/lesabre/viii-2000-2005/remont/suspension-front/#suspension-general-diagnosis) .
If these measurements are out of specifications, inspect for improper weight distribution, collision damage, or worn or damaged suspension components.

RADIAL TIRE LEAD/PULL CORRECTION

DEFINITION: The deviation of the vehicle from a straight path on a level road with no pressure on the steering wheel.

Did you perform the Vehicle Leads/Pull diagnostic table in Suspension General Diagnosis? If yes, go to next step. If no, go to «VEHICLE LEADS/PULLS»(/buick/lesabre/viii-2000-2005/remont/suspension-front/#suspension-general-diagnosis__vehicle-leadspulls) .
Road test the vehicle to verify the complaint. Select a smooth level surface to perform the test. Does the condition exist? If yes, go to next step. If no, system is okay.
Cross-switch the front tire/wheel assemblies. Road test the vehicle. Does the vehicle still lead/pull? If yes, go to next step. If no, system is okay.
Does the vehicle lead/pull in the opposite direction? If yes, go to next step. If no, go to «BRAKING ACTION UNEVEN»(/buick/lesabre/viii-2000-2005/remont/mechanical-hydraulic/#disc-brakes) .
Cross-switch the left front tire/wheel assembly with the left rear tire/wheel assembly. Road test the vehicle. Does the vehicle still lead/pull? If yes, go to next step. If no, go to step 7 .
Cross-switch the right front tire/wheel assembly with the right rear tire/wheel assembly. Road test the vehicle. Does the vehicle still lead/pull? If yes, go to «BRAKING ACTION UNEVEN»(/buick/lesabre/viii-2000-2005/remont/mechanical-hydraulic/#disc-brakes) . If no, go to step 8 .
Replace the left rear tire. After replacing tire, go to step 9 .
Replace the right rear tire. After replacing tire, go to next step.
Verify proper vehicle operation. Does the original condition still exist? If yes, go to step 1 . If no, system is okay.

Scheme 6

Scheme 6: SPECIAL TOOLS

Scheme 7

Suspension - General Diagnosis Buick LeSabre VIII