Test Description

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

1. 4:  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. 6:  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. 7:  Tire and wheel assemblies that exhibit excessive runout when measured off of the vehicle could cause a vibration disturbance.
4. 8:  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. 13:  Brake rotors that exhibit excessive imbalance could contribute to, or possibly cause a vibration disturbance.
6. 14:  A hub/axle flange and/or wheel studs that exhibit excessive runout could cause a vibration disturbance.
7. 15:  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. 19:  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. 21:  Vibration disturbances could be affected by, or possibly caused by, components that are susceptible to steering input and/or torque-load input.
10. 23:  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.