Transaxle casing for automatic transmission

A transaxle casing structure for accommodating a transmission gear set having a plurality of rotary members arranged on a common axis, the transaxle casing comprising:

• a cover wall enclosing said transmission gear set;
• an oil sump disposed below said transmission gear set for receiving lubricating oil therein;
• and
• a continuous partition disposed between a radially outermost one of said rotary members of said transmission gear set and said cover wall and generally extending from a top of said outermost rotary member to a bottom of said outermost rotary member, an oil return passage being defined between the partition and said cover wall for guiding lubricating oil into said oil sump, said oil return passage having a first opening between one end of said partition and said cover wall and a second opening between another end of said partition and said cover wall.