Transmission

A gearbox you design yourself on the Car Design Stand (the Engine Stand, which now has a second tab for it). It couples the shaft behind it to the shaft in front at the ratio of the gear it is in.

Designing one

Open the stand, switch to the Transmission tab, and set the number of gears (2 to 6) and each gear's ratio in steps of 0.05, from 0.5 to 5.0. A ratio is input turns per output turn: 3.5 is a low gear, 0.8 an overdrive. Drop a sample of the metal in the sample slot, put paper in, and Print. Craft the Transmission Blueprint with that metal's ingots (2 per gear) to get the block. The blueprint is kept.

Using it

Place it with its back to the input shaft and its front to the output. Right click shifts up through neutral, the gears and reverse; sneak right click shifts down. Reverse is first gear's ratio, backwards. In neutral nothing is coupled. A program or the Driver's Seat can shift it too, through its gear input.

Wear

Shifting while the input shaft is turning fast grinds the teeth, in proportion to the speed and softer metals worse. A badly worn transmission jumps out of gear under load, more often the more worn it is. Stopping, or going through neutral, costs nothing, and running it never wears it.