RAM 3500 Truck 4WD L6-5.9L DSL Turbo VIN C (2002)
Actuator: Description and Operation
Front Axle - 248FBI / AXLE VACUUM MOTOR
DESCRIPTION
The disconnect axle control system consists of: Shift motor. Indicator switch. Vacuum switch. Vacuum harness (Fig. 26).
OPERATION
The shift motor receives a vacuum signal from the switch mounted on the transfer case when the vehicle operator wants to switch from two wheel drive
mode to four wheel drive mode, or vice versa. When this signal is received, the shift motor begins to move the shift fork and collar within the axle
housing. In the four wheel drive mode, the shift collar connects the axle intermediate shaft to the axle shaft to supply engine power to both front wheels.
In two wheel drive mode, the shift collar is disengaged from the intermediate shaft and the intermediate shaft is allowed to free-spin. When the two shafts
are disengaged, the load on the engine is reduced, thereby providing better fuel economy and road handling.
