A power transfer assembly for a four-wheel drive vehicle includes first
and second output shafts and a drive mechanism operable to selectively
transfer drive torque from a driven input shaft to the output shafts. The
drive mechanism includes a differential assembly, a planetary gear
assembly and first and second mode clutches. The first mode clutch is
operable with the planetary gear assembly to increase the rotary speed of
the first output shaft which, in turn, causes a corresponding decrease in
the rotary speed of the second output shaft. The second mode clutch is
operable with the planetary gear assembly to decrease the rotary speed of
the first output shaft so as to cause an increase in the rotary speed of
the second output shaft. A control system controls actuation of both mode
clutches.