A drive axle assembly includes a pair of axleshafts connected to a pair of
wheels and a drive mechanism for selectively coupling a driven input
shaft to one or both of the axleshafts. The drive mechanism includes
first and second drive units that can be selectively engaged to control
the magnitude of the drive torque transferred and the relative rotary
speed between the input shaft and the axleshafts. Each drive unit
includes a planetary gearset disposed between the input shaft and its
corresponding axleshaft, a bi-directional overrunning clutch and a mode
clutch that may be activated to cause the planetary gearset to establish
different speed ratio drive connections between the input shaft and the
axleshaft. A control system including an electronic control unit (ECU)
and sensors are provided to control actuation of the mode clutches so as
to control the side-to-side traction characteristics of the drive axle
assembly.