Shift Overlap Control

When overlap gearshift takes place, freewheels (one-way clutches) are not used but are replaced by suitable actuation of the relevant clutches. This both enables weight and space to be saved.

The electronic-hydraulic shift action is obtained by means of various valves in the transmission control module (TCM) and main control valve body, actuated by pressure regulators. They engage or disengage the relevant clutches or brakes at the correct moments.

Output is always by the ring gear of the second, downstream planetary gear set.