Transmission Shift Lever Jumpout

Transmission shift lever jumpout is a truck system dynamics problem that is caused by engine/transmission pitching in response to rough road input. Severe rotational motion imposes inertial forces on the shift lever system, potentially causing the shift rail to move to neutral. Dynamic testing and analysis has led to suggestions for system design improvement including lever geometry optimization and engine mount stiffness and damping improvement. A counterweight addition to the lever system will also stabilize the dynamics.