Normal operation of the reverse interlock mechanism is that when the drive is in neutral or forward and the lift jack shaft is in its fully up position, the outdrive must undergo a sizable backward force to overcome the spring latches that secure it to the locating pin (running aground, etc..). In reverse, the spring-latches are locked in the fully engaged position, preventing the drive from tilting upward. When the jack shaft of the lift is lowered, it contacts the yoke and holds the interlock's thrust rod from rising into the yoke, thus releasing the spring latches as the drive is raised. If the electromechanical lift raises/lowers your drive as expected, it sounds as if your unit is working as intended..
