The power shift planetary transmission consists of the directional section and the speed section, and operates in the following modes: FIRST GEAR FORWARD, FIRST GEAR REVERSE, SECOND GEAR FORWARD, and SECOND GEAR REVERSE. Listed are the key components and steps of operation for the directional section of the transmission.
Forward direction: Power from the engine is transmitted to the input shaft, driving the sun gears. The ring gear of the forward planetary gear set is held by the forward clutch pack, while the reverse sun gear is rotating the planet gears. The forward planetary sun gear rotates in the same direction of the input shaft, causing the planet gears to rotate in the opposite direction. The held ring gear causes the planet gears to revolve in the same direction as the sun gear rotation, causing the planet carrier to rotate in the same direction.