Abstract: A control system (158) for a multi-speed change gear transmission (10) of the type permitting preselection of a selected engaged gear ratio is provided. The control system includes an operator actuated selector switch (160) for selection of a desired gear ratio and providing a signal (R,F) indicative thereof, and actuation devices (166, 168, 152) for shifting the transmission into the selected gear ratio in response to said signals. Preselect prohibit valves (162, 164) are interposed the selector switch and actuation devices to block the transmittal of said signals and to maintain the transmission in the currently engaged gear ratio until operator actuation of a prohibit release switch (172) provides a signal (C) indicating operator request for execution of the preselected gear change.