If the area you are referring to is lower down and below the shift tower, it could be the end of the idler shaft. That can also leak, similar to what Truckernix mentioned above. There are no frost plugs, do not drill it out. If you want to fix it you may have to remove the tranny and at least partially disassemble. The ends of the idler shaft, and the ends of the shift rails can be coated with permatex and that will help a bit.
Last edited by Lightholder's Dad; Fri May 29 2020 08:31 PM.