Preventing overspeeding of an engine by inhibiting improper gear selection

A method of preventing overspeeding of an engine and attached ancillary devices in a vehicle, eg track loader, includes inhibiting a gear change via an electronic control module. The gear change is inhibited if 1) a brake accumulator pressure in above a preselected value, 2) the vehicle ground speed is above a certain value, 3) an improper gear change is attempted and 4) a torque converter output speed is above a preselected value. In another embodiment the torque converter lock-up solenoid activated in response to torque converter output speed which is compared to selected values to engage or disengage a loc-up clutch. In a further embodiment engine over speeding is prevented by engine braking using a compression release braking system (CRBS), which responds to engine RPM, and may be used in a manual or automatic mode. A destroked variable displacment pump having an adjustable swashplate may be controlled in response to engine RPM, thereby preventing engine overspeeding.