Automatic transmission with feedback passage for preventing reverse flow

An automatic transmission for a vehicle comprising:

• an elongated casing having a longitudinal axis parallel to the length of the vehicle and divided into front and rear compartments by an internal wall generally perpendicular to said axis, each of said front and rear compartments having a sump for collecting oil;
• a passage provided through said internal wall, said passage providing fluid communication for said collected oil between the sump of said front compartment and the sump of said rear compartment;
• reverse flow inhibit means for allowing oil to flow from the sump of said rear compartment to the sump of said front compartment while inhibiting the oil from flowing in the reverse direction, said reverse flow inhibit means including a flap valve pivotally suspended from said internal wall, within said front compartment at a position covering said passage, said flap valve having a center of gravity located so that said flap valve is normally open with a gap between said flap valve and said internal wall, said flap valve pivoting against said internal wall and thereby closing said passage responsive to sudden starting or acceleration of the vehicle.