long term storage leak

I have had car for 6 years now,in winter I put in storage,had minor transmission pan leak.well I fixed damaged bolt hole threads in may.no leaks all summer long.checked on the car this week and there's huge puddle on transmission oil on the floor.not the pan leaking.but is wet buy selector shaft and front pump area.i was told this is normal due to convertor drain back from sitting form nov. to now with out starting it.by the was it's 904 trans.is this correct?before repair it also did this,i just though it was because of leaking pan.but that has been fixed.