Begin the system diagnosis by reviewing the Transfer Case Disassembled View , Transfer Case Description and Operation , and Rear Drive Axle Description and Operation . Reviewing the description and operation information helps you determine the correct symptom diagnostic procedure when a malfunction exists. Reviewing the description and operation information also helps you determine if the condition described by the customer is normal operation. Refer to Symptoms - Transfer Case in order to identify the correct procedure for diagnosing the system and where the procedure is located.