A vehicle powertrain incorporates a planetary gearset which is coupled
with a front wheel drive mechanism and a rear wheel drive mechanism. The
planetary gearset is controlled by two torque-transmitting mechanisms to
establish an input member of the planetary gearset as well as a grounded
member for the planetary gearset in combinations that will provide a
two-wheel low drive ratio, a two-wheel high drive ratio, a four-wheel low
drive ratio, and a four-wheel high drive ratio.