Multi-speed transmission with countershaft gearing

A powertrain comprising:

• a transmission input member;
• a power source for generating a torque in the input member;
• a first intermediate shaft;
• a second intermediate shaft concentric with the first intermediate shaft;
• a clutch selectively engagable to couple the transmission input member with one of the first and second intermediate shafts;
• a first and a second countershaft;
• a first set of gears connected for common rotation with the first intermediate shaft and intermeshing with a first selectable set of gears to form a first plurality of co-planar gear sets, wherein each of the gears of the first selectable set of gears is connectable for common rotation with one of the first and second countershafts for selectively transferring the torque to the countershafts when the clutch is engaged;
• a second set of gears connected for common rotation with the second intermediate shaft and intermeshing with a second selectable set of gears to form a second plurality of co-planar gear sets, wherein each of the gears of the second selectable set of gears is connectable for common rotation with one of the first and second countershafts for selectively transferring the torque to one of the countershafts when the clutch is engaged;
• an output shaft disposed radially outward of the second intermediate shaft;
• a first transfer gear coupled to one of the first and second countershafts for transferring torque from the first and second countershafts to the output shaft;
• a first idler gear rotatable about a first idler axis and intermeshing with at least one of the first selectable sets of gears;
• and
• a second idler gear rotatable about the idler axis and intermeshing with the at least one of the first set of gears.