🧠 This maze of channels is basically the hydraulic brain of an old-school automatic transmission, using pressurized oil to decide when and how the car shifts. ⠀ The part is called a valve body, and transmission fluid is pumped through its intricate passages toward different valves, clutches and bands. ⠀ In older automatics, changes in vehicle speed and engine load altered hydraulic pressures, physically moving shift valves and routing fluid to the correct clutch circuits. ⠀ Those clutches then lock or release different parts of the planetary gearsets, which is how the transmission creates multiple gear ratios without you touching a clutch pedal. ⠀ So the “hydraulic calculus” joke is surprisingly accurate, because before computers took over much of the decision-making, automatics were essentially using fluid pressure, springs, valves and carefully sized passages to perform mechanical logic. ⠀ Modern transmissions still use hydraulic pressure to apply their clutches, but electronic sole...