Begin the system diagnosis by reviewing the system Description and 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. Refer to Symptoms - Suspension General Diagnosis in order to identify the correct procedure for diagnosing the system and where the procedure is located.
| IMPORTANT | The following steps must be completed before using the symptom tables. |
Review the system description and operation in order to familiarize yourself with the system functions. Refer to the appropriate description and operation
- «Front Suspension Description and Operation»(/cadillac/sts/i-2004-2007/remont/suspension-front/#front-suspension-system__front-suspension-description-and-operation) in Front Suspension
- «Rear Suspension Description and Operation»(/cadillac/sts/i-2004-2007/remont/suspension-rear/#rear-suspension-system__rear-suspension-description-and-operation) in Rear Suspension
- «General Description»(/cadillac/sts/i-2004-2007/remont/wheel-tire-system/#tires-and-wheels__general-description) in Tires and Wheels
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. Refer to «Label - Vehicle Certification, Tire Place Card, Anti-Theft and Service Parts ID»(/cadillac/sts/i-2004-2007/remont/hoistjack/#general-information) in General Information.
Symptom List
Refer to a symptom diagnostic procedure from the following list in order to diagnose the symptom
- «Ride Diagnosis»(/cadillac/sts/i-2004-2007/remont/suspension-front/#suspension-general-diagnosis__ride-diagnosis)
- «Vehicle Leads/Pulls»(/cadillac/sts/i-2004-2007/remont/suspension-front/#suspension-general-diagnosis__vehicle-leadspulls)
- «Body Leans or Sways in Corners»(/cadillac/sts/i-2004-2007/remont/suspension-front/#suspension-general-diagnosis__body-leans-or-sways-in-corners)
- «Suspension Bottoms»(/cadillac/sts/i-2004-2007/remont/suspension-front/#suspension-general-diagnosis__suspension-bottoms)
- «Memory Steer»(/cadillac/sts/i-2004-2007/remont/suspension-front/#suspension-general-diagnosis__memory-steer)
- «Poor Directional Stability»(/cadillac/sts/i-2004-2007/remont/suspension-front/#suspension-general-diagnosis__poor-directional-stability)
- «Noise Diagnosis - Front Suspension»(/cadillac/sts/i-2004-2007/remont/suspension-front/#suspension-general-diagnosis__noise-diagnosis-front-suspension)
- «Noise Diagnosis - Rear Suspension»(/cadillac/sts/i-2004-2007/remont/suspension-front/#suspension-general-diagnosis__noise-diagnosis-rear-suspension)
- «Struts or Shock Absorbers On-Vehicle Testing»(/cadillac/sts/i-2004-2007/remont/suspension-front/#suspension-general-diagnosis__struts-or-shock-absorbers-on-vehicle-testing)
- «Wheel Bearings Diagnosis»(/cadillac/sts/i-2004-2007/remont/suspension-front/#suspension-general-diagnosis__wheel-bearings-diagnosis)
- «Radial Tire Lead/Pull Correction»(/cadillac/sts/i-2004-2007/remont/wheel-tire-system/#tires-and-wheels__radial-tire-leadpull-correction) in Tires and Wheels
Ride Diagnosis
| IMPORTANT |
|---|
| Verify the vehicle suspension package RPO. |
Vehicle Leads/Pulls
| Step | Action | Yes | No |
|---|
| DEFINITION: At a constant highway speed on a typical straight road, lead/pull is the amount of effort required at the steering wheel to maintain the vehicle straight path. |
| 1 | Did you review the General Description and perform the visual/physical inspections? | Go to Step 2 | Go to Symptoms - Suspension General Diagnosis |
| 2 | Road test the vehicle in order to verify the complaint. Does the vehicle operate normally? | System OK | Go to Step 3 |
| 3 | Inspect the tire/wheel assemblies for: Correct tire pressure - Refer to the tire placard. Correct tire size - Refer to the tire placard. Abnormal tire wear or damage Did you find and correct the condition? | Go to Step 9 | Go to Step 4 |
| 4 | Perform the Radial Tire Lead/Pull Correction in Tires and Wheels. Did you find and correct the condition? | Go to Step 9 | Go to Step 5 |
| 5 | Inspect and correct/adjust the suspension and steering systems for: Vehicle trim height - Refer to Trim Height Specifications in Wheel Alignment. Excessively worn, loose, or damaged components Did you find and correct the condition? | Go to Step 9 | Go to Step 6 |
| 6 | Inspect the brake system for brake drag. With the vehicle suspended on a hoist, brake drag can be identified by rotating each wheel several times and observing whether more force is needed to rotate the left wheel or the right wheel. Refer to Diagnostic Starting Point - Disc Brakes in Disc Brakes. Did you find and correct the condition? | Go to Step 9 | Go to Step 7 |
| 7 | Inspect the wheel alignment and adjust as necessary. Refer to Measuring Wheel Alignment in Wheel Alignment. Did you correct the condition? | Go to Step 9 | Go to Step 8 |
| 8 | Inspect the steering gear for unequal effort. The vehicle must be suspended on a hoist, the engine running, and the transmission in park or neutral. Grasp the tire assembly and manually simulate a turn from the left of center and the right of center observing whether more force is needed to turn to the left or to the right. If this condition exists, replace the steering gear. Did you correct the condition? | System OK | Go to Step 3 |
| 9 | Operate the vehicle in order to verify the repair. Did you correct the condition? | System OK | Go to Step 3 |
Body Leans or Sways in Corners
| Step | Action | Yes | No |
|---|
| 1 | Did you review the General Description and perform the necessary inspections? | Go to Step 2 | Go to Symptoms - Suspension General Diagnosis |
| 2 | Verify the vehicle leans or sways in corners. Does the vehicle operate normally? | System OK | Go to Step 3 |
| 3 | Inspect the following components for wear or damage: The front coil springs The rear coil springs Are the components worn or damaged? | Go to Step 5 | Go to Step 4 |
| 4 | Inspect the stabilizer shaft link for wear or damage. Is the stabilizer shaft link worn or damaged? | Go to Step 6 | Go to Step 2 |
| 5 | Replace the springs. Refer to the appropriate procedure: Shock, Shock Component, and/or Spring Replacement in Front Suspension Coil Spring Replacement in Rear Suspension Did you complete the repair? | Go to Step 7 | |
| 6 | Replace the stabilizer shaft link. Refer to the appropriate procedure: Stabilizer Shaft Link Replacement in Front Suspension Stabilizer Shaft Link Replacement in Rear Suspension Did you complete the repair? | Go to Step 7 | |
| 7 | Operate the vehicle in order to verify the repair. Did you correct the condition? | System OK | Go to Step 3 |
Body Leans or Sways in Corners
Suspension Bottoms
| Step | Action | Yes | No |
|---|
| 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. |
| 1 | Did you review the General Description and perform the necessary inspections? | Go to Step 2 | Go to Symptoms - Suspension General Diagnosis |
| 2 | Verify that the suspension bottoms. Does the vehicle operate normally? | System OK | Go to Step 3 |
| 3 | Check for vehicle overloading. Refer to Label - Vehicle Certification, Tire Place Card, Anti-Theft and Service Parts ID in General Information. Is the vehicle overloaded? | Go to Step 6 | Go to Step 4 |
| 4 | Inspect the vehicle trim height. Refer to Trim Height Inspection Procedure in Wheel Alignment. Is the vehicle trim height incorrect? | Go to Step 7 | Go to Step 5 |
| 5 | Inspect the struts and shock absorbers. Refer to Struts or Shock Absorbers On-Vehicle Testing . Are the components in need of replacement? | Go to Step 8 | Go to Step 9 |
| 6 | Remove the excess weight from the vehicle. Did you remove the excess weight from the vehicle? | Go to Step 9 | |
| 7 | Correct the vehicle trim height. Refer to Trim Height Inspection Procedure in Wheel Alignment. Did you complete the repair? | Go to Step 9 | |
| 8 | Replace the components as necessary. Did you complete the repair? | Go to Step 9 | |
| 9 | Operate the vehicle in order to verify the repair. Did you correct the condition? | System OK | Go to Step 3 |
Memory Steer
| Step | Action | Yes | No |
|---|
| DEFINITION: The steering wheel does not return to center after completing a turn. |
| 1 | Did you review the General Description and perform the necessary inspections? | Go to Step 2 | Go to Symptoms - Suspension General Diagnosis |
| 2 | Verify that memory steer is present. Does the system operate normally? | System OK | Go to Step 3 |
| 3 | Ensure that all of the tires are inflated to the correct pressure. Refer to Tire Inflation Pressure Specifications in Maintenance and Lubrication. Has the inspection/adjustment been performed? | Go to Step 4 | |
| 4 | 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? | Go to Step 5 | System OK |
| 5 | Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle in General Information. Disconnect both of the outer tie rod ends from the steering knuckles. Refer to Rack and Pinion Outer Tie Rod End Replacement in Power Steering System. Use your hands in order to move the steering gear linkage to check for a binding condition. Is the power steering gear linkage abnormally difficult to move? | Go to Step 9 | Go to Step 6 |
| 6 | Use your hands in order to rotate the steering knuckle/ball joints. Is the steering knuckle/ball joints abnormally difficult to rotate? | Go to Step 7 | Go to Step 8 |
| 7 | Replace the lower control arm. Refer to Lower Control Arm Replacement or Shock, Shock Component, and/or Spring Replacement in Front Suspension. Did you complete the repair? | Go to Step 8 | Go to Step 8 |
| 8 | 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? | Go to Step 9 | Go to Step 12 |
| 9 | Disconnect the intermediate shaft. IMPORTANT: Do NOT rotate the steering wheel more than one complete revolution. 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? | Go to Step 10 | Go to Step 11 |
| 10 | Repair the steering column as necessary. Did you complete the repair? | Go to Step 13 | |
| 11 | 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. Did you complete the repair? | Go to Step 12 | |
| 12 | 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. Did you complete the repair? | Go to Step 13 | |
| 13 | Operate the vehicle in order to verify the repair. Did you correct the condition? | System OK | Go to Step 3 |
| IMPORTANT |
|---|
| Do NOT rotate the steering wheel more than one complete revolution. |
Poor Directional Stability
| Step | Action | Yes | No |
|---|
| DEFINITION: Driver is unable to maintain consistent, predictable vehicle driving control in any direction. |
| 1 | Did you review the General Description and perform the necessary inspections? | Go to Step 2 | Go to Symptoms - Suspension General Diagnosis |
| 2 | Verify that the directional stability is poor. Does the system operate normally? | System OK | Go to Step 3 |
| 3 | Inspect the stabilizer shaft, links, and insulators for wear or damage. Replace as necessary. Refer to the following procedures in Front Suspension: Stabilizer Shaft Replacement Stabilizer Shaft Link Replacement Stabilizer Shaft Insulator Replacement Does the vehicle still exhibit poor directional stability? | Go to Step 4 | System OK |
| 4 | Inspect the lower control arms, ball joints, and tie rods for wear or damage. Repair as necessary. Refer to the following procedures: Lower Control Arm Replacement in Front Suspension Rack and Pinion Outer Tie Rod End Replacement in Power Steering System Does the vehicle still exhibit poor directional stability? | Go to Step 5 | System OK |
| 5 | Inspect the wheel bearings/hubs for looseness or excessive lateral runout. Refer to Wheel Bearings Diagnosis . Does the vehicle still exhibit poor directional stability? | Go to Step 6 | System OK |
| 6 | Inspect the vehicle trim height. Refer to Trim Height Inspection Procedure in Wheel Alignment. Repair as necessary. Does the vehicle still exhibit poor directional stability? | Go to Step 7 | System OK |
| 7 | Inspect and adjust the wheel alignment as necessary. Refer to Measuring Wheel Alignment in Wheel Alignment. Does the vehicle still exhibit poor directional stability? | Go to Step 8 | System OK |
| 8 | Inspect the steering column for looseness. Refer to Looseness in Steering Column in Steering Wheel and Column. Repair as necessary. Did you complete the repair? | Go to Step 9 | |
| 9 | Inspect the steering gear mounting bolts for looseness. Refer to Fastener Tightening Specifications in Power Steering. Repair as necessary. Did you complete the repair? | Go to Step 10 | |
| 10 | Operate the vehicle in order to verify the repair. Did you correct the condition? | System OK | Go to Step 3 |
Poor Directional Stability
Noise Diagnosis - Front Suspension
| Step | Action | Yes | No |
|---|
| 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. |
| 1 | Did you review the General Description and perform the necessary inspections? | Go to Step 2 | Go to Symptoms - Suspension General Diagnosis |
| 2 | IMPORTANT: Compare this vehicle to an identical vehicle in order to determine if the customer's concern is a normal operating characteristic of the vehicle. Attempt to duplicate the noise. Road test the vehicle.Is the front suspension noisy? | Go to Step 3 | System OK |
| 3 | Shift the transmission into Park. Turn the ignition off. Bounce the front of the vehicle in order to duplicate the noise. Is the noise present? | Go to Step 4 | Go to Step 5 |
| 4 | Bounce the front of the vehicle. Use J 39570 Chassis Ear in order to locate the source of the noise. Repair or replace the suspect components as necessary. Did you complete the repair? | Go to Step 25 | |
| 5 | Raise and support the vehicle. Refer to J 39570 in General Information. Inspect all of the front suspension components for any damage. Are any components damaged? | Go to Step 6 | Go to Step 7 |
| 6 | Repair any damaged components. Did you complete the repair? | Go to Step 25 | |
| 7 | Inspect the tires for proper inflation. Refer to Tire Inflation Pressure Specifications in Maintenance and Lubrication. Correct the tire inflation pressure as necessary. Inspect the tires for unusual wear. Refer to Tire Diagnosis - Irregular or Premature Wear in Tires and Wheels. Does either tire exhibit unusual tread wear? | Go to Step 8 | Go to Step 10 |
| 8 | Rotate the tires. Refer to Tire Rotation in Tires and Wheels. Road test the vehicle. Is the noise now emitted from the rear of the vehicle? | Go to Step 9 | Go to Step 10 |
| 9 | Replace the tires that are causing the noise. Did you complete the repair? | Go to Step 25 | |
| 10 | Ensure that the ball joints and steering linkage are lubricated, if applicable. Lubricate/replace as necessary. Did you service any components? | Go to Step 25 | Go to Step 11 |
| 11 | NOTE: Refer to Fastener Notice in Cautions and Notices. Ensure that all of the wheel nuts are tightened to the correct specification. Tighten as necessary. Refer to Fastener Tightening Specifications in Tires and Wheels.Did you tighten any wheel nuts? | Go to Step 25 | Go to Step 12 |
| 12 | Use your hands in order to push and pull the shock. Is the shock loose? | Go to Step 13 | Go to Step 15 |
| 13 | Inspect the shock module fasteners for the correct fastener tightening specification. Tighten as necessary. Refer to Fastener Tightening Specifications in Front Suspension. Use your hand to push and pull the shock module. Is the shock module loose? | Go to Step 14 | Go to Step 25 |
| 14 | Replace the loose or worn shock module components. Refer to Shock, Shock Component, and/or Spring Replacement in Front Suspension. Did you complete the repair? | Go to Step 25 | |
| 15 | Use your hands in order to push and pull on the stabilizer shaft. Is the stabilizer shaft loose? | Go to Step 16 | Go to Step 20 |
| 16 | Inspect all of the stabilizer shaft fasteners. Tighten as necessary. Refer to Fastener Tightening Specifications in Front Suspension. Use your hands in order to push and pull on the stabilizer shaft. Is the stabilizer shaft loose? | Go to Step 17 | Go to Step 25 |
| 17 | Observe the location of the stabilizer shaft looseness. Is the looseness observed at the stabilizer shaft links? | Go to Step 18 | Go to Step 20 |
| 18 | Replace the stabilizer shaft links. Refer to Stabilizer Shaft Link Replacement in Front Suspension. Did you complete the repair? | Go to Step 25 | |
| 19 | Replace the stabilizer shaft insulators and/or brackets. Refer to Stabilizer Shaft Insulator Replacement in Front Suspension. Did you complete the repair? | Go to Step 25 | |
| 20 | Inspect the control arms for looseness or movement. Is any looseness or movement observed? | Go to Step 21 | Go to Step 23 |
| 21 | Inspect the control arm fasteners for the correct fastener tightening specification. Refer to Fastener Tightening Specifications in Front Suspension. Tighten as necessary. Inspect the control arm for looseness. Is the control arm loose? | Go to Step 22 | Go to Step 25 |
| 22 | Replace any worn or loose control arm bushings. Refer to Lower Control Arm Replacement in Front Suspension. Did you complete the repair? | Go to Step 25 | |
| 23 | Start the engine with the drive wheels off of the ground. Shift the transmission into Drive. CAUTION: Do not spin the drive wheels faster than 55 km/h (35 mph) as indicated by the speedometer. This limit is necessary because the speedometer indicates only one half of the actual wheel speed when one drive wheel is spinning and the other drive wheel is stopped. Personal injury and damage may result from high speed spinning. IMPORTANT: This step will require the assistance of another person to maintain the drive train speed. Do not use the cruise control to maintain the drivetrain speed. Increase the drive wheel speed until the noise is at the most audible level. IMPORTANT: Do not allow the J 39570 to contact any moving components. Use J 39570 in order to locate the source of the noise. Does either wheel bearing exhibit noise? | Go to Step 24 | Go to Step 8 |
| 24 | Replace the wheel bearings. Refer to Wheel Bearing/Hub Replacement - Front (AWD) or Wheel Bearing/Hub Replacement - Front (RWD) in Front Suspension. Did you complete the repair? | Go to Step 25 | |
| 25 | Operate the vehicle in order to verify the repair. Did you correct the condition? | System OK | Go to Step 3 |
| IMPORTANT |
|---|
| Compare this vehicle to an identical vehicle in order to determine if the customer's concern is a normal operating characteristic of the vehicle. |
| CAUTION |
|---|
| Do not spin the drive wheels faster than 55 km/h (35 mph) as indicated by the speedometer. This limit is necessary because the speedometer indicates only one half of the actual wheel speed when one drive wheel is spinning and the other drive wheel is stopped. Personal injury and damage may result from high speed spinning. |
| IMPORTANT |
|---|
| This step will require the assistance of another person to maintain the drive train speed. Do not use the cruise control to maintain the drivetrain speed. |
| IMPORTANT |
|---|
| Do not allow the J 39570 to contact any moving components. |
Noise Diagnosis - Front Suspension
Noise Diagnosis - Rear Suspension
| Step | Action | Yes | No |
|---|
| 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. |
| 1 | Did you review the General Description and perform the necessary inspections? | Go to Step 2 | Go to Symptoms - Suspension General Diagnosis |
| 2 | Verify that the rear suspension is noisy. Is the rear suspension noisy? | Go to Step 3 | System OK |
| 3 | 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 present? | Go to Step 4 | Go to Step 5 |
| 4 | Bounce the rear of the vehicle. Use a J 39570 Chassis Ear in order to locate the source of the noise. Repair or replace the suspect components as necessary. Did you complete the repair? | Go to Step 23 | |
| 5 | Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle in General Information. Inspect all of the rear suspension components for any damage. Are any components damaged? | Go to Step 6 | Go to Step 7 |
| 6 | Repair or replace any damaged components. Did you complete the repair? | Go to Step 23 | |
| 7 | Inspect the tires for proper inflation. Refer to Tire Inflation Pressure Specifications in Maintenance and Lubrication. Correct the tire inflation pressure as necessary. Inspect the tires for unusual wear. Refer to Tire Diagnosis - Irregular or Premature Wear in Tires and Wheels. Does either tire exhibit unusual tread wear? | Go to Step 8 | Go to Step 10 |
| 8 | Rotate the tires. Refer to Tire Rotation in Tires and Wheels. Road test the vehicle. Is the noise now emitted from the front of the vehicle? | Go to Step 9 | Go to Step 10 |
| 9 | Replace the tires that are causing the noise. Did you complete the repair? | Go to Step 23 | |
| 10 | Ensure that the park brake cable and the spare tire are secured properly. Did you service any components? | Go to Step 23 | Go to Step 11 |
| 11 | NOTE: Refer to Fastener Notice in Cautions and Notices. Ensure that all of the wheel nuts are tightened to the correct specification. Tighten as necessary. Refer to Fastener Tightening Specifications in Tires and Wheels.Did you tighten any of the wheel nuts? | Go to Step 23 | Go to Step 12 |
| 12 | Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle in General Information. Use your hand to push and pull the shock absorbers. Is either shock absorber loose? | Go to Step 13 | Go to Step 15 |
| 13 | Inspect the shock absorber fasteners for the correct fastener tightening specification. Tighten as necessary. Refer to Fastener Tightening Specifications in Rear Suspension. Use your hands in order to push and pull the shock absorber. Is the shock absorber loose? | Go to Step 14 | Go to Step 23 |
| 14 | Replace the loose or worn shock absorber. Refer to Shock Absorber Replacement in Rear Suspension. Did you complete the repair? | Go to Step 23 | |
| 15 | Use your hands in order to push and pull on the rear suspension adjustment links. Is the rear suspension adjustment link loose? | Go to Step 16 | Go to Step 18 |
| 16 | Inspect the rear suspension adjustment link fasteners. Tighten as necessary. Refer to Fastener Tightening Specifications in Rear Suspension. Use your hands in order to push and pull on the rear suspension adjustment link. Is the rear suspension adjustment link loose? | Go to Step 17 | Go to Step 23 |
| 17 | Replace the rear suspension adjustment link as necessary. Did you complete the repair? | Go to Step 23 | |
| 18 | Use your hands in order to push and pull on the rear suspension trailing arm. Is either rear suspension trailing arm loose? | Go to Step 19 | Go to Step 21 |
| 19 | Inspect the rear suspension trailing arm fasteners for the correct fastener tightening specification. Tighten as necessary. Refer to Fastener Tightening Specifications in Rear Suspension. Use your hands in order to push and pull on the rear suspension trailing arm. Is either rear suspension trailing arm loose? | Go to Step 20 | Go to Step 23 |
| 20 | Replace any worn or loose rear suspension trailing arm bushings. Did you complete the repair? | Go to Step 23 | |
| 21 | 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. IMPORTANT: Do not allow the J 39570 to contact any moving components. Use a J 39570 in order to locate the source of the noise. Does either wheel bearing exhibit excessive noise? | Go to Step 22 | Go to Step 8 |
| 22 | Replace the wheel bearings. Refer to Wheel Bearing/Hub Replacement - Rear in Rear Suspension. Did you complete the repair? | Go to Step 23 | |
| 23 | Operate the vehicle in order to verify the repair. Does the system operate normally? | System OK | Go to Step 3 |
| IMPORTANT |
|---|
| Do not allow the J 39570 to contact any moving components. |
Noise Diagnosis - Rear Suspension
Ball Joint Inspection
| Step | Action | Values | Yes | No |
|---|
| 1 | Did you review the General Description and perform the necessary inspections? | | Go to Step 2 | Go to Symptoms - Suspension General Diagnosis |
| 2 | Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle in General Information. Clean the ball joint and inspect the seal for damage. Is the ball joint seal damaged? | | Go to Step 6 | Go to Step 3 |
| 3 | Check the wheel bearing for looseness. Refer to Wheel Bearings Diagnosis in Suspension General Diagnosis. Did you find and correct the condition? | | Go to Step 7 | Go to Step 4 |
| 4 | IMPORTANT: Remove tension from the ball joints. Check the ball joint for horizontal looseness using the following procedure: Position the J 8001 Dial Indicator against the lowest outboard point of the wheel rim. Rock the wheel in and out while reading the dial indicator. Does the dial indicator measure greater than the specified value? | 3.18 mm (0.125 in) | Go to Step 6 | Go to Step 5 |
| 5 | IMPORTANT: Remove tension from the ball joints. Check the ball joint for vertical looseness using the following procedure: Install the J 8001 . Move the ball joint up and down while reading the dial indicator. Does the dial indicator measure greater than the specified value? | 3.18 mm (0.125 in) | Go to Step 6 | Go to Step 7 |
| 6 | Replace the ball joint. Refer to Lower Control Arm Replacement or Shock, Shock Component, and/or Spring Replacement in Front Suspension or Lower Control Arm Replacement or Upper Control Arm Replacement in Rear Suspension. Did you complete the repair? | | Go to Step 7 | |
| 7 | Operate the system in order to verify the repair. Did you correct the condition? | | System OK | Go to Step 2 |
| IMPORTANT |
|---|
| Remove tension from the ball joints. |
| IMPORTANT |
|---|
| Remove tension from the ball joints. |
Struts or Shock Absorbers On-Vehicle Testing
| Step | Action | Yes | No |
|---|
| 1 | Did you review the General Description and perform the necessary inspections? | Go to Step 2 | Go to Symptoms - Suspension General Diagnosis |
| 2 | Verify that the malfunction is present. Does the vehicle operate normally? | System OK | Go to Step 3 |
| 3 | IMPORTANT: A light film of oil on the top portion of the reservoir is normal. Inspect each shock absorber for external fluid leakage.Is the shock absorber leaking? | Go to Step 7 | Go to Step 4 |
| 4 | Inspect the vehicle trim height. Refer to Trim Height Inspection Procedure in Wheel Alignment. Is the vehicle trim height correct? | Go to Step 5 | Go to Step 6 |
| 5 | 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? | Go to Step 8 | Go to Step 7 |
| 6 | Replace the front spring or the rear spring. Refer to Shock, Shock Component, and/or Spring Replacement in Front Suspension. Refer to Coil Spring Replacement in Rear Suspension. Did you complete the repair? | Go to Step 8 | |
| 7 | Replace the strut or shock absorber. Refer to Shock, Shock Component, and/or Spring Replacement in Front Suspension. Refer to Shock Absorber Replacement in Rear Suspension. Did you complete the repair? | Go to Step 8 | |
| 8 | Operate the vehicle in order to verify the repair. Did you correct the condition? | System OK | Go to Step 3 |
| IMPORTANT |
|---|
| A light film of oil on the top portion of the reservoir is normal. |
Struts or Shock Absorbers On-Vehicle Testing
Wheel Bearings Diagnosis
| Step | Action | Values | Yes | No |
|---|
| 1 | Did you review the General Description and perform the necessary inspections? | | | Go to Symptoms - Suspension General Diagnosis |
| 2 | Road test the vehicle in order to verify the customer's complaint. Does the vehicle operate normally? | | System OK | Go to Step 3 |
| 3 | Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle in General Information. Inspect for tire or wheel damage. Refer to Tire and Wheel Assembly Runout Measurement - On-Vehicle in Vibration Diagnosis and Correction. Did you find and correct the condition? | | Go to Step 7 | Go to Step 4 |
| 4 | Install the J 39570 Chassis Ear. Road test the vehicle to verify the location of the wheel bearing noise. Did you locate the source of the wheel bearing noise? | | Go to Step 6 | Go to Step 5 |
| 5 | IMPORTANT: Support the vehicle by the lower control arms or the rear axle to prevent movement during wheel bearing/hub inspection. Mount and secure the J 8001 Dial Indicator. Ensure that the dial indicator contacts the vertical surface of the wheel as close as possible to the top wheel stud. Push and pull on the top of the tire in order to inspect the total travel indicated by the dial indicator. Is the measurement greater then the specified value? | 0.27 mm (0.005 in) | Go to Step 6 | System OK |
| 6 | Replace the wheel bearing. Refer to Wheel Bearing/Hub Replacement - Front (AWD) or Wheel Bearing/Hub Replacement - Front (RWD) in Front Suspension or Wheel Bearing/Hub Replacement - Rear in Rear Suspension. Did you complete the repair? | | Go to Step 7 | |
| 7 | Road test the vehicle to verify the repair. Does the vehicle operate normally? | | System OK | Go to Step 3 |
| IMPORTANT |
|---|
| Support the vehicle by the lower control arms or the rear axle to prevent movement during wheel bearing/hub inspection. |
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. Refer to «Label - Vehicle Certification, Tire Place Card, Anti-Theft and Service Parts ID»(/cadillac/sts/i-2004-2007/remont/hoistjack/#general-information) in General Information.
- Check the fuel level. Add additional weight if necessary to simulate a full tank.
- Ensure the rear compartment is empty except for the spare tire.
- Ensure 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.
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.
- 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»(/cadillac/sts/i-2004-2007/remont/wheel-alignment/#wheel-alignment-system__trim-height-specifications) in Wheel Alignment.
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.
- 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.
- Measure the vertical distance between the centerline of the inboard rear lower control arm bolt and centerline of the outboard rear lower control arm bolt.
- 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»(/cadillac/sts/i-2004-2007/remont/wheel-alignment/#wheel-alignment-system__trim-height-specifications) in Wheel Alignment.
- If these measurements are out of specifications, inspect for the following conditions: Improper weight distribution Collision damage Worn or damaged suspension components
Special Tools
Special Tools Illustration Tool Number/ Description J 8001 Dial Indicator J 39570 Chassis Ear
