Co je tohle v automatické převodovce?

Je to valve body (doslova těleso ventilů).

Z angl.Wiki: The valve body inside the transmission is responsible for directing hydraulic pressure to the appropriate bands and clutches. It receives pressurized fluid from the main pump and consists of several spring-loaded valves, check balls, and servo pistons.

Reddit: What you are looking at is the 'wiring' for an analog computer that used hydraulic fluid instead of electrons. For each electronic component in an analog computer there is a hydraulic 'equivalent'. Pressure approximates voltage and orifice size provides resistance. Check balls function like diodes, valves act like transistors. Spring loaded accumulators act like capacitors.