Th400 leak

I have a turbo 400 that i can not get to quit leaking out of the very end of the tailshaft[leaks when it sits].I have but a couple of tailshaft seals in and and a new bushing,and a new yoke but still no help.I have even gotten another dipstick to make sure the level is correct.It runs good just will not hold in its fluid..:banghead: .any ideas would be appreciated..

Have the tailhousing "dye checked" to be sure it's not cracked. It may be...

Jim