Rear Clutch

Rear clutch is engaged at 1st-3rd gear of D/2/L range. When it is engaged, forward sun gear of the planetary gear rotates.

Power flow: 

Input shaft--> Rear clutch retainer--> Rear clutch--> Rear clutch hub-> Forward sun gear--> Short pinion

Fig 1: Rear Clutch Power Flow Diagram

Courtesy of KIA MOTORS AMERICA, INC.