2007 S80 32 transmission level
 

Where is the level plug on the Aisin Warner 5 speed automatic transmission? I would expect to find it on the side of the unit but I don't see one. This transmission has no dipstick so the correct level of fluid might be determined by removing the fill plug and the level plug and then adding fluid until it just starts to flow out of the level plug. Anyone got any tips?
PH