TRANSGO TF1 QUESTION

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.
Just tap it just deep enough so that the set screw is below the pan rail. I would also find the set screws before you tap it.