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Front Drive Axle Description and Operation
Selectable Four Wheel Drive (S4WD) Front Axle Description and Operation

The Selectable Four Wheel Drive (S4WD) Front Axle consist of the following components:

1. Differential Carrier Housing
2. Differential Case Assembly
3. Inner Axle Shaft
4. Intermediate Shaft Bearing Assembly (located on the right side of the oil pan)
5. Electric Motor Actuator

The front axle on Selectable Four Wheel Drive (S4WD) model vehicles uses a disconnect feature mounted on the right side of the oil pan in order to engage and disengage the front axle. When the driver engages the 4WD system, the Transfer Case Control Module sends a signal to the electric motor actuator to energize and extend the plunger inside. The extended plunger moves the clutch fork and clutch fork sleeve across from the clutch fork outer gear that is splined to the right side wheel drive shaft to the clutch fork inner gear that is splined to the inner axle shaft. The locking of the two gears allows the axle to operate in the same manner as a semi-floating rear axle. A propeller shaft connects the transfer case to the front axle. The differential carrier assembly uses a conventional ring and pinion gear set to transmit the driving force of the engine to the wheels. The open differential allows the wheels to turn at different rates of speed while the axle continues to transmit the driving force. This prevents tire scuffing when going around corners and premature wear on internal axle parts. The ring and pinion set and the differential are contained within the carrier. The axle identification number is located on top of the differential carrier assembly or on a label on the bottom of the right half of differential carrier assembly. The wheel drive shafts are completely flexible assemblies consisting of inner and outer constant velocity CV joints protected by thermoplastic boots and connected by a wheel drive shaft.
Automatic Four Wheel Drive (A4WD) Front Axle Description and Operation

The Automatic Four Wheel Drive (A4WD) Front Axle consist of the following components:

1. Differential Carrier Housing
2. Differential Case Assembly
3. Inner Axle Shaft
4. Intermediate Shaft bearing Assembly (located on the right side of the oil pan)

The front axle on Automatic Four Wheel Drive (A4WD) model vehicles do not have a disconnect feature in order to engage and disengage the front axle. The Automatic Four Wheel Drive system uses the same differential carrier assembly and intermediate shaft bearing assembly, but the clutch fork, the clutch fork sleeve and the inner/outer gears have been replaced with a single splined sleeve that connects the inner axle shaft directly to the right side wheel drive shaft. This connection allows the right side wheel drive shaft and the intermediate axle shaft to be directly connected to the differential case assembly. It also results in having the wheel drive shafts, the intermediate axle shaft and the propeller shaft to spin continuously. When the transfer case is active, the clutch assembly within the transfer case controls the amount of torque applied to the front axle. The remaining components are the same as the selectable four wheel drive axle.