TRANSGO TF1 QUESTION

Just pack the tap with grease and tap it slowly. There is no drilling required. The set screw and tap size is 3/8-16 and I start off with an 1/8” orifice. The other thing that you can do is use a shop vac while tapping the hole.
My trans is still on the stand.....Upon closer look, I will do what you suggest. It looks like I can pack something deep into the passage as a safety measure. I have a spiral fluted tap, which tends to pull the chips outward as it advances, and a bit of grease as well.