I found something very interesting, when looking in the lua for the game, particularly this line: Code: local straightCutGearCoef = device.straightCutGearIndexes[device.gearIndex] and 1 or 0 I'm pretty sure this has something to do with a sound, which is why it was commented out. After adding in a placeholder sound, and adding the following flag to the gearbox jbeam: Code: "straightCutGearCoef": 1, nothing happens. Is there any sort of flag that tells the game whether or not a gearbox has straight-cut gears?