Diagnosis And Testing: Notes

WHEEL BALANCE AND VIBRATION 

Tire and wheel imbalance, wheel runout and tire road force variation can cause vehicles to exhibit steering wheel vibration and or seat vibration.

VEHICLES WITH A VIBRATION OR SHAKE 

The following procedure is to identify, prevent, and correct vibration.

Vehicle vibration or shake may have many root causes. It is important to properly identify the root cause in order to properly diagnose the vehicle. Typically the vibration may be felt in the steering wheel or seat and will be most noticeable at highway speeds 96 km/h (60 mph) and greater.

Tire pressure is often inflated to the maximum sidewall pressure at the vehicle assembly plant to prevent "flat spots" on tires during new vehicle shipping and vehicle storage. Inflating tires to the maximum sidewall tire pressure helps to preserve the integrity of the tire and reduces potential technical issues. Over inflation can cause unnecessary vehicle shake, therefore proper cold inflation pressure is critical to minimize vehicle shake.

Considerations: 

• Where is the vibration felt? (seat, steering wheel, floor pan)
• At what speed does the vibration occur? (low or high mph)
• How many miles are on the vehicle? (higher mileage could indicate vehicle or suspension wear)
• Are there any suspension components that may require replacement of bushings, ball joints, or other suspension components? (see suspension diagnosis)
• When was the vibration first noticed? (at purchase or following a specific event, such as a pothole, off-road, or other collision)