For 1990-2009 cars

This section describes the techniques and procedures for correcting the following types of vibrations:

• | Tire and wheel shake

• | Launch shudder

• | Exhaust moan

• | Engine firing frequency

• | Driveline vibration

### Identifying the Concern

Important: Do NOT attempt to repair a normal condition, or the customer will probably be convinced that the vehicle has a problem. Customer satisfaction becomes extremely difficult after this point.

The first step in diagnosing a vibration concern is to identify the exact vibration that concerns the customer.

It is a good idea to ride with the customer, making the comparison with the customer present and explain the situation.

Sometimes the vibration can be duplicated at a given speed. Other vibrations may not be as evident and may require further troubleshooting by performing a road test with the customer in the vehicle in order to determine the specific vibration complaint.

Ask the following questions when attempting to identify a vibration complaint:

• | At what speed is the vibration the worst?

• | Can the vibration be felt? If so, where?

• | Can the vibration be heard? If so, what does the noise sound like?

• | Does the engine or the vehicle load affect the vibration?

• | Does the vibration occur in more than one gear range?

• | When did the vibration first appear?

The answers to these questions will help in duplicating and diagnosing the vibration.

If you suspect that the vibration is normal, compare the vibration with a vehicle that is equipped in the same way, including the following factors:

• | Body style

• | Engine option

• | Engine driven accessories

• | Transmission type

• | Tire size

• | Suspension performance type

• | Axle ratio

### A Process of Elimination

You must understand a few basic concepts before attempting to diagnose a vibration. As in any diagnostic process, you must perform the following steps:

• | Gather the information

• | Decipher the information

• | Make your correction based on the results

Road test the vehicle and inspect the vehicle in a manner which systematically eliminates different components. This process supplements the information which you have received from the customer concerning the complaint. Concentrating efforts on the areas that have not been eliminated will make repairs faster and more effective.