THIS PRELIMINARY INFORMATION COMMUNICATION PROVIDES INFORMATION TO THE TECHNICIAN ON HOW TO DIAGNOSE VEHICLES WITH VARIOUS NOISES ASSOCIATED WITH FOUR WHEEL DRIVE OPERATION. BEFORE BEGINNING ANY DIAGNOSIS IT IS IMPERATIVE TO REVIEW THE SYMPTOMS - TRANSFER CASE IN SERVICE INFORMATION AND PERFORM THE NECESSARY INSPECTIONS. IN ALL CASES THE COMPLAINT VEHICLE SHOULD BE COMPARED TO ANOTHER LIKE VEHICLE BEFORE BEGINNING ANY REPAIRS.