Review the system operations in order to familiarize yourself with the system functions. Refer to Transfer Case Disassembled View , Transfer Case Description and Operation , and Rear Drive Axle 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 .
| • | 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 levels and the proper viscosities. |
| • | 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 and ensure you are not trying to correct a normal condition. |
Test the vehicle under the same conditions that the customer reported in order to verify the system is operating properly.
Refer to a symptom diagnostic procedure from the following list in order to diagnose the symptom: