Symptom Chart: Notes
Diagnostics in this service information assume a certain skill level and knowledge of Ford-specific diagnostic practices. Refer to: Diagnostic Methods .
In most circumstances the PCM sets a DTC to help guide with diagnostics. Refer to the DTC Chart before using the Symptom Chart. The condition column lists the vehicle condition. The Possible Sources column lists a detailed vehicle condition. The Action column lists the action to be performed to determine the cause of the condition. Each action lists the components that can cause the system and the individual components in that system. The components are listed in order of disassembly. Use the list of components and the required action to focus on disassembly inspections for the root cause of the concern.
| Symptom | Possible Sources | Action |
|---|---|---|
| The transfer case unit makes noise | Tire inflation pressure Tire and wheel size Fluid level Internal components |
MAKE SURE all tires and wheels are the same size and brand and the inflation pressures are correct. FILL with the correct type and amount of lubricant. OPERATE the vehicle in all gears. If there is noise in the transmission in NEUTRAL, or in some gears and not in others, REMOVE and REPAIR the transmission. If there is noise in all gears, INSTALL a new transfer case unit. |
| Leaking fluid from the transfer case unit vent | Transfer case unit is over filled | |
| Leaking transmission fluid | Transfer case unit intermediate shaft seal Transfer case unit compression seal |
Refer to Analysis of Leakage . |
| Leaking gear lubricant from the seals | The transfer case unit vent is plugged (located on top of the transfer case unit) Damaged seals |
Check for the leaking seal or seals and remove and replace with new seals. Refer to: (-) |
| Vehicle has no or inadequate torque at rear wheels | Rear axle Transfer case unit mechanical failure |
Refer to: Axle Assembly
. Refer to: (-) |
| Vehicle binds in a turn or resists turning/pulsates or shudders in a straight line | Wheels/tires Brake system Wheel bearings Halfshafts ABS system |
Refer to: Wheels and Tires
. Refer to: Brake System . Refer to: Suspension System - AWD . Refer to: Front Drive Halfshafts . Refer to: Anti-Lock Brake System (ABS) and Stability Control . |
| Loss of AWD function or partial AWD function | Transfer case unit overheating | INSPECT the duct that cools the transfer case unit sump is free and clear of debris. |