4l60e leaks

[Graycharles88]

Hello. I lost my transfer in an 02 z71 Silverado with 5.3l. pulled transfer and had tranny fluid where it should be dry. Pulled tranny extension to change seal, and there isn't any on the outside you need to disassemble the tranny to fix. But the issue is there is a drilled hole in the bottom going to the tranny pan??? This is supposed to be a dry connection. Is this a mod a tranny shop might do to keep fluid from being lost?? Thanks in advance.