my transmission has had a small leak somewhere for over a year now. i have changed the gasket three times with no luck, so i used it as an excuse to put the mag hi-tech unit on. well it still leaks, so i am thinking the other culprit might be the o-ring on the filler tube. searched the service manual over and cannot find a spec listed anywhere. does anyone know the size of this o-ring? btw, the transmission line couplers all seem to be ok. thanks in advance for your help.