Steering: Testing and Inspection
DIAGNOSIS AND TESTING
VIBRATION (SHIMMY) ABOVE 50 MPH (80 KMH)
Vehicles equipped with a solid front axle can be susceptible to steering shimmy. Often this condition is due to modifications to the vehicle that may involve aftermarket equipment that may not be compatible with the vehicle architecture or is not intended for on-road use. For original equipment, this condition can be corrected with routine inspection for properly maintained wheels and tires and replacement of damaged or worn components.
NOTE: This Diagnosis and Testing covers a self-sustaining vibration (shimmy) of the vehicle and steering wheel while driving at speeds typically above 50 MPH (80 KMH)
NOTE: This applies to vehicles equipped with a solid front axle only.
1. Test drive the vehicle to verify customer complaint.
NOTE: It may be necessary to drive the vehicle in the environment (i.e., same type of terrain, such as uneven pavement, railroad tracks, etc.) that the customer experienced the condition in order to properly diagnose the condition and confirm that the repairs corrected the concern.
2. Is the vehicle equipped with aftermarket components or other modifications (e.g. lift kits, wheels, suspension components or tires) that can affect the performance of or wear upon steering components?
1. Yes: notify the owner and document in the repair order that: i. the express limited warranties do not cover conditions or damage caused by the use of aftermarket components, improper maintenance, or impact damage; and ii. the use of aftermarket components, improper maintenance, and impact damage can cause steering shimmy or otherwise accelerate the wear of steering components that cause steering shimmy; and iii. the dealership will inspect steering components that were supplied by the manufacturer for defects in material, workmanship and factory preparation and determine if necessary repairs are covered under the terms of the warranties applicable to the vehicle. With customer authorization, proceed to Step #3.
2. No: Proceed to Step #3.
3. Inspect the vehicle steering components for any damage.
4. Was any visible damage present?
1. Yes: Recommend the replacement of all damaged components
2. No: Proceed to Step #5.
5. Are the tires on the vehicle properly inflated to the correct pressure?
1. Yes: Proceed to Step #6.
2. No: Refer to the tire placard on the inside of the driver's door and inflate the tires to the specified pressure and proceed to Step #6.
6. Do the tires exhibit a condition of excessive wear, cupping or damage?
1. Yes: Recommend replacement if required or perform tire rotation to locate the best tires onto the front axle.
2. No: Proceed to Step #7.
NOTE:
Refer to the proper diagnosing and testing procedures indicated in the service information
7. Verify proper wheel and tire balance.
8. Does the vehicle still exhibit the condition?
1. Yes: Proceed to Step #9.
2. No: Return the vehicle to the customer.
9. Recommend the replacement of the steering damper.
10. Does the vehicle still exhibit the condition?
1. Yes: Proceed to Step #11.
2. No: Return the vehicle to the customer.
11. Does the track bar show signs of excessive wear or damage?
1. Yes: Proceed to Step #12.
2. No: Proceed to Step #14.
NOTE:
Refer to the proper diagnosing and testing procedures indicated in the service information.
12. Recommend the replacement of the track bar.
13. Does the vehicle still exhibit the condition?
1. Yes: Proceed to Step #14.
2. No: Return the vehicle to the customer.
14. Do the tie rods show signs of excessive wear or damage?
1. Yes: Proceed to Step #15.
2. No: Proceed to Step #16.
NOTE:
Refer to the proper diagnosing and testing procedures indicated in the service information.
15. Recommend the replacement of worn tie rods.
16. Does the drag link show signs of excessive wear or damage?
1. Yes: Proceed to Step #17.
2. No: Proceed to Step #18.
NOTE:
Refer to the proper diagnosing and testing procedures indicated in the service information.
17. Recommend the replacement of the worn drag link.
18. Verify vehicle wheel alignment is within specification and adjust accordingly.
19. Does the vehicle still exhibit the condition?
1. Yes: Proceed to Step #20.
2. No: Return the vehicle to the customer.
20. Do the ball joints show signs of excessive wear or damage?
1. Yes: Proceed to Step #21.
2. No further diagnosis required.
NOTE:
Refer to the proper diagnosing and testing procedures indicated in the service information.
21. Recommend the replacement of worn ball joints.
22. Does the vehicle still exhibit the condition?
1. Yes: Further diagnosis is required.
2. No: Return the vehicle to the customer.
STEERING SYSTEM DIAGNOSIS CHARTS
NOTE:
There are two diagnosis charts following that cover PERFORMANCE ISSUES and NOISE, VIBRATION AND HARSHNESS (NVH) ISSUES.
NOTE: For any performance issues, check for DTCs related to the steering system. Verify the correct software and calibration files are loaded in the Electric Power Steering (EPS) system.
PERFORMANCE ISSUES
NOISE, VIBRATION AND HARSHNESS (NVH) ISSUES
NOTE:
* A light clunk may be felt or heard during steering wheel reversal while vehicle is stationary. This results from internal steering gear rack movement at the bushings and in no way affects the performance of the steering system. This movement may be felt in the steering components during steering wheel reversal.