During the last 10-15 years, vehicle design and engineering
have dramatically changed due to the following factors:
| • | Decreased fuel supplies |
| • | Corporate Average Fuel Economy requirements |
| • | Ability to withstand collision |
| • | Rising customer expectations |
Vehicle designs have evolved from full-frame construction to lighter
unibody designs. These designs transfer noise and vibration much more readily.
General Motors has greatly reduced the use of heavier and smoother running
V8 engines, replacing these engines with lighter, more fuel-efficient 4-cylinder
and 6-cylinder engines. During this same period, options such as the following
have become more and more popular:
Such options increase engine load and can also generate unwanted noise
and vibration.
Customer perception of quality can be directly linked to the presence
or absence of unwanted noise and vibration. A technician's ability to quickly
diagnose and repair a noise or vibration directly affects that customer's
loyalty to the dealership. Technicians who are capable of satisfying this
need will be highly regarded and in great demand.
The intent of this section of the service manual is to provide a systematic
approach to vehicle vibration diagnosis and correction. By using Strategy
Based Diagnosis and troubleshooting philosophies covered in this section,
technicians will be able to provide effective and timely repairs.
