Important: The following steps must be completed before using the analysis tables
or the symptom tables.
- Perform the
Vibration Analysis - Road Testing
table before using the other Vibration Analysis tables
or the Symptom tables in order to effectively diagnose the customer's concern.
The use of Vibration Analysis - Road Testing will first provide duplication
of virtually any vibration concern and then identify the correct procedure
for diagnosing the area of concern which has been duplicated.
- Review the following Vibration Diagnostic Process.
- Review the general descriptions to familiarize yourself with vibration
theory and terminology, the J 38792-A
, Electronic Vibration Analyzer (EVA) 2 and the J 38792-VS
, Vibrate Software.
Reviewing this information will help you determine whether the condition
described by the customer is a potential operating characteristic or not.
Refer to the following:
Vibration Diagnostic Process
Important: Using the following steps of the vibration diagnostic process will help
you to effectively narrow-down and pin-point the search for the specific source
of a vibration concern and to arrive at an accurate repair.
- Gather specific information on the customer's vibration concern.
- Perform the road testing steps in sequence as identified in Vibration
Analysis - Road Testing in order to duplicate the customer's concern and evaluate
the symptoms of the concern under changing conditions. Observe what the vibration
feels like and what it sounds like. Observe when the symptoms first appear,
when they change, and when they cease.
- Determine if the customer's vibration concern is truly an abnormal
condition or something that is potentially an operating characteristic of
the vehicle.
- Systematically eliminate or "rule-out" possible vehicle
systems.
- Focus diagnostic efforts on the remaining vehicle system and systematically
eliminate or "rule-out" possible components of that system.
- Make a repair on the remaining component, or components, which
have not been eliminated systematically, and must therefore be the cause of
the vibration.
- Verify that the customer's concern has been eliminated or at least
brought to an acceptable level.
- Again perform the road testing steps in sequence as identified
in Vibration Analysis - Road Testing in order to verify that the vehicle did
not have more than one vibration occurring.
Preliminary Visual/Physical Inspection
| • | Inspect for aftermarket equipment and modifications which could
affect the operation of the vehicle rotating component systems. |
| • | Inspect the easily accessible or visible components of the vehicle
rotating component systems for obvious damage or conditions which could cause
the symptom. |
| • | Inspect the tire inflation pressures for the proper pressure. |
Diagnostic Aids
Improper component routing or isolation, or components which are worn
or faulty may be the cause of intermittent conditions that are difficult to
duplicate. If the vibration concern could not be duplicated by following
the steps of the Vibration Diagnostic Process, refer to
Vibration Diagnostic Aids
.
