GM Service Manual Online
For 1990-2009 cars only

Test Description

The numbers below refer to the step numbers in the diagnostic table:

  1. A buildup of foreign material on a tire and wheel assembly and/or a damaged, abnormally or excessively worn tire and wheel assembly could cause a vibration disturbance.

  2. Tire and wheel assemblies that exhibit excessive runout when measured while mounted on the vehicle, may or may not be contributing to, or causing a vibration disturbance. On-vehicle runout, if present, could contribute to, or cause a vibration disturbance, but the cause of the on-vehicle runout may not be the tire and wheel assemblies.

  3. Tire and wheel assemblies that exhibit excessive runout when measured off of the vehicle could cause a vibration disturbance.

  4. Tire and wheel assemblies that exhibit marginal runout (within acceptable limits, but close to the maximum) when measured off of the vehicle could still be contributing to a vibration disturbance, if its mating hub/axle flange also exhibits marginal runout. When the tire and wheel assembly and the hub axle flange are mounted to each other, the combined stack-up of their marginal amounts of runout could combine to produce an excessive amount of runout, which could cause a vibration disturbance.

  5. Brake rotors and/or brake drums that exhibit excessive imbalance could contribute to, or possibly cause a vibration disturbance.

  6. A hub/axle flange and/or wheel studs that exhibit excessive runout could cause a vibration disturbance.

  7. When the tire and wheel assembly and the hub axle flange are mounted to each other, the combined stack-up of their marginal amounts of runout could combine to produce an excessive amount of runout, which could cause a vibration disturbance. Match-mounting or vectoring the tire and wheel assembly to the hub/axle flange will modify the amount of combined runout.

  8. Force variation may be present in a tire and wheel assembly that exhibited acceptable balance and runout. Force variation, if present, could contribute to, or cause a vibration disturbance.

  9. Vibration disturbances could be affected by, or possibly caused by, components that are susceptible to steering input and/or torque-load input.

  10. On-vehicle balancing, or finish-balancing can be used to reduce small amounts of imbalance which may be present as a result of the combined stack-up of the tire and wheel assembly with other components which may exhibit marginal balance.

Step

Action

Yes

No

1

Has the Vibration Analysis - Road Testing table been completed?

Go to Step 2

Go to Vibration Analysis - Road Testing

2

Based on the Vibration Analysis - Road Testing table, is the concern first-order tire and wheel assembly related?

Go to Step 4

Go to Step 3

3

Based on the Vibration Analysis - Road Testing table, is the concern second-order, or higher-order tire and wheel assembly related?

Go to Step 19

Go to Vibration Analysis - Road Testing

4

Visually inspect the tire and wheel assemblies for the following:

    • Debris buildup, such as packed mud, undercoating, ice/snow buildup, road tar, etc.
    • Damage, abnormal or excessive wear

Refer to Tire and Wheel Inspection .

Do any of the tire and wheel assemblies exhibit any of the conditions listed?

Go to Step 5

Go to Step 6

5

  1. Remove the debris from the tire and wheel assemblies.
  2. Replace the damaged, abnormally or excessively worn wheels or tires as necessary. Refer to Tire Mounting and Dismounting in Tires and Wheels.

Did you complete the repair or replacement?

Go to Step 24

--

6

Measure the on-vehicle runout of the tire and wheel assemblies. Refer to Tire and Wheel Assembly Runout Measurement - On-Vehicle .

Does the runout measurement indicate a runout concern?

Go to Step 7

Go to Step 11

7

Measure the off-vehicle runout of the tire and wheel assemblies. Refer to Tire and Wheel Assembly Runout Measurement - Off Vehicle .

Does the runout measurement indicate a runout concern?

Go to Step 20

Go to Step 8

8

Are any of the tire and wheel assembly runout measurements marginal (within acceptable limits, but close to the maximum)?

Go to Step 9

Go to Step 14

9

  1. Match-mount (vector) the tire-to-wheel for each tire and wheel assembly with marginal runout. Refer to Tire-to-Wheel Match-Mounting (Vectoring) .
  2. Remeasure the runout of each match-mounted tire and wheel assembly. Refer to Tire and Wheel Assembly Runout Measurement - Off Vehicle .

Were you able to significantly reduce the amount of tire and wheel assembly runout?

Go to Step 10

Go to Step 20

10

Remeasure the on-vehicle runout of the tire and wheel assemblies. Refer to Tire and Wheel Assembly Runout Measurement - On-Vehicle .

Does the remeasurement indicate a runout concern?

Go to Step 14

Go to Step 24

11

Inspect the balance of the tire and wheel assemblies. Refer to Tire and Wheel Assembly Balancing - Off Vehicle .

Are any or the tire and wheel assemblies out of balance?

Go to Step 12

Go to Step 13

12

Balance the tire and wheel assemblies as necessary. Refer to Tire and Wheel Assembly Balancing - Off Vehicle .

Were you able to achieve balance?

Go to Step 24

Go to Vibration Diagnostic Aids

13

  1. Inspect the brake rotors and brake drums for damage.
  2. Inspect the balance of the brake rotors and brake drums. Refer to Brake Rotor/Drum Balance Inspection .

Are any of the brake rotors and/or brake drums damaged and/or out of balance?

Go to Step 17

Go to Step 18

14

Measure the runout of the hub/axle flanges and the wheel studs. Refer to Hub/Axle Flange and Wheel Stud Runout Inspection .

Does the runout measurement indicate a runout concern?

Go to Step 16

Go to Step 15

15

  1. Match-mount (vector) the tire and wheel assemblies-to-hub/axle flanges. Refer to Tire and Wheel Assembly-to-Hub/Axle Flange Match-Mounting .
  2. Remeasure the on-vehicle runout of tire and wheel assemblies. Refer to Tire and Wheel Assembly Runout Measurement - On-Vehicle .

Were you able to significantly reduce the amount of on-vehicle tire and wheel assembly runout?

Go to Step 24

Go to Step 2

16

Replace components as required. Refer to the following procedures as necessary:

    •  Wheel Stud Replacement in Front Suspension
    •  Wheel Stud Replacement in Rear Suspension
    •  Front Wheel Hub, Bearing, and Seal Replacement in Front Suspension
    •  Rear Axle Shaft Replacement in Rear Drive Axle

Did you complete the replacement?

Go to Step 24

--

17

Replace the brake rotors and/or brake drums as necessary. Refer to the appropriate procedure(s):

    •  Brake Rotor Replacement in Disc Brakes
    •  Brake Drum Replacement in Drum Brakes

Did you complete the replacement?

Go to Step 24

--

18

Inspect for radial and lateral force variation. Refer to Tire and Wheel Assembly Isolation Test .

Were you able to isolate one or more of the tire and wheel assemblies as the cause of the disturbance?

Go to Step 20

Go to Step 21

19

Inspect for radial and lateral force variation. Refer to Tire and Wheel Assembly Isolation Test .

Were you able to isolate one or more of the tire and wheel assemblies as the cause of the disturbance?

Go to Step 20

Go to Step 22

20

Replace the tire(s) and/or wheel(s) as necessary. Refer to Tire Mounting and Dismounting in Tires and Wheels.

Did you complete the replacement?

Go to Step 24

--

21

Perform the Vibration Analysis - Hub/Axle Input table. Refer to Vibration Analysis - Hub and/or Axle Input .

Did you find and correct a condition?

Go to Step 24

Go to Step 23

22

Perform the Vibration Analysis - Hub/Axle Input table. Refer to Vibration Analysis - Hub and/or Axle Input .

Did you find and correct a condition?

Go to Step 24

Go to Vibration Diagnostic Aids

23

Finish-balance the tire and wheel assemblies ON-vehicle. Refer to Tire and Wheel Assembly Balancing - On-Vehicle .

Did you complete the on-vehicle finish balancing?

Go to Step 24

--

24

  1. Install or connect any components that were removed or disconnected during diagnosis.
  2. Perform the Vibration Analysis - Road Testing table. Refer to Vibration Analysis - Road Testing .

Is the vibration still present?

Go to Step 2

System OK