IIA Main Gearbox - What is this?

[JackIIA]

When the Transfer Case is buttoned up against the Main Gear Case, the circled female bolt hole (below) in the Main Gear Case is covered by the TX Case.

It doesn't appear to serve any purpose. So what is it there for? Hopefully I haven't forgotten a part somewhere.

It's threaded too.

[Les Parker]

Hello there,

The pic. is a bit fuzzy but there should be a hole in the rear of the main gear case for the end of the reverse idler shaft to come through.
Give me a call to discuss it,