A transmission drive system (TDS) has two AC induction traction motors,
each operatively coupled to two semi-independent coaxial traction shafts,
and two AC induction steer motors coaxially mounted on a common steer
axis parallel to the coaxial traction shafts. A steering gear assembly,
preferably between the traction and steering motors, has a common steer
input shaft operatively connected to the two AC induction steering
motors. Two planetary gear sets have the two traction shafts being
operatively connected with one of a two planet gear carriers, or two ring
gears, respectively. The other of the planet gear carriers or the ring
gears are operatively connected with each other. Two offset gears mounted
to the steer input shaft and meshing with two sun gears, respectively,
including a reversing idler gear interposed between one of the two offset
gears and one of the two sun gears.