Active Components In Different Gear Positions

Clutches:
A clutch connects 2 rotating units together.
C1: Connects the input shaft with the rear planetary gear train's (P1) ring gear.
C2: Connects the input shaft with the common sun wheel of the planetary gear trains (P1 and P2).
C3: Connects the lower planetary gear train's (P3) planet carrier with the sun wheel.

Brakes:
A brake is mounted in the transmission casing. On activation, it locks the rotating unit to the casing.
B1: Locks the primary shaft's sun wheel to prevent it from rotating.
B2: Prevents the primary shaft's sun wheel from rotating anti-clockwise.
B3: Locks the primary shaft's ring wheel.
B4: Locks the lower planetary gear train's (P3) sun wheel.

Freewheel:
F1: Prevents the front planetary gear train's (P2) ring gear from rotating anti-clockwise when B2 is applied.
F2: Prevents the front planetary gear train's (P2) ring gear from rotating anticlockwise.
F3: Prevents the lower planetary gear train's (P3) sun wheel from rotating clockwise.

Solenoid valve S1
Controls shifting: 1-2, 2-1 and 3-4, 4-3 through clutch C2 and brakes B1, B2 and B3.

Solenoid valve S2
Controls shifting: 2-3, 3-2 through clutch C3 and brake B4.

NOTE: Clutch C1 is controlled by the hydraulic system's manual shifting valve and is activated in all "forward gears".

^ B2 activated but inoperative.