Visual/Physical Inspection
| • | Inspect for aftermarket devices, which could affect the operation of the vehicle. |
| • | Inspect the easily accessible or visible system components for obvious damage or a condition which could cause the symptom. |
| • | Check for correct lubricant level and proper viscosity. |
| • | Verify the exact operating conditions under which the concerns exist. Note factors such as speed, road conditions, ambient temperature, and other specifics. |
| • | Compare the driving characteristics or sounds, if applicable, to a known good vehicle and make sure you are not trying to correct a normal condition. |
| • | The rear axle activation and operation may be checked by positioning the four wheels off the ground, starting the vehicle, and selecting he drive position. A properly operating rear axle and transfer case will rotate all four wheels at equal RPM. Fully
apply the parking brake, the rear will stop turning. Apply the throttle while watching the rear wheels. They will rotate slightly as the driveline winds-up. This indicates the AWD is functioning. |
| • | Factors that may contribute to an inoperative rear axle include: |
| - | A mini spare or different size tires |
| - | A fluid over temperature condition |
| - | A defective rear axle assembly |
| - | An inoperative transfer case assembly |
Intermittents
Test the vehicle under the same conditions that the customer reported in order to verify the system is operating properly.
Noise Acceptability
A gear driven unit will produce a certain amount of noise. Some noise is acceptable and audible at certain speeds, or under various driving conditions, such as a newly paved blacktop road. Slight noise is not detrimental to the operation of the axle and
is considered normal.
Symptom List
Refer to a symptom diagnostic procedure from the following list in order to diagnosis the symptom :
