GM Service Manual Online
For 1990-2009 cars only

Strategy Based Diagnostics

Review the system operations in order to familiarize yourself with the system functions. Refer to Rear Axle Disassembled Views , Rear Drive Axle Description and Operation , and Wheel Drive Shafts Description and Operation . All diagnosis on a vehicle should follow a logical process. Strategy based diagnostics is a uniform approach for repairing all systems. The diagnostic flow may always be used in order to resolve a system condition. The diagnostic flow is the place to start when repairs are necessary. For a detailed explanation, refer to Strategy Based Diagnosis .

Visual/Physical Inspection

    • Inspect for aftermarket devices which could affect the operation of the vehicle. Refer to Checking Aftermarket Accessories .
    • Inspect the easily accessible or visible system components for obvious damage or conditions which could cause the symptom.
    • Inspect for the correct lubricant level and the proper viscosity.
    • Verify the exact operating conditions under which the concern exists. Note factors such as vehicle speed, road conditions, ambient temperature, and other specifics.
    • Compare the driving characteristics or sounds, if applicable, to a known good vehicle to ensure you are not trying to correct a normal condition.

Intermittent

Test the vehicle under the same conditions that the customer reported in order to verify the system is operating properly.

Symptom List

Refer to a symptom diagnostic procedure from the following list in order to diagnose the symptom:

    •  Diagnostic Starting Point - Vibration Diagnosis and Correction
    •  Diagnostic Starting Point - Automatic Transmission
    •  Symptoms - Propeller Shaft
    •  Noisy in Drive
    •  Noisy When Coasting
    •  Constant Noise
    •  Noisy on Turns
    •  Rear Axle Lubricant Leak Diagnosis