There is a gasket that goes between the torque tube and trans. I think I paid $12 for the set of gaskets. Might as well replace them. Something like the link below. You can find them cheaper.
http://www.classicpartsusa.com/prod...tbJbDtUHmmRaSpWDUk8kLf0Gd0xoCFncQAvD_BwE

Chris