'64 Barracuda trans/shift lines question?

Could be the o-ring that goes around where the gear goes into the tailshaft or it could be the inner lining of the cable is worn and its leaking right where the cable joins the end. I think you can still get the OEM replacement cables thru MOPAR. At least for the 67 and up. Don't know how yours hooks to the speedo in the dash.

Larry