Abstract: A closure device, or more specifically a hand held plug, for engagement over the end of the output shaft of an automobile transmission subsequent to the disconnection of an automobile driveshaft from said transmission output shaft. The closure plug includes two co-axially aligned tubular portions separated from one another by a transversely disposed fluid barrier. The tubular portions have different nominal diameters so as to be operable with transmissions having output shafts and associated seals of different diameters. The closure plug is utilized to preclude the potential loss of transmission fluid through the wall of the transmission housing after disconnection of the automobile drive shaft.