Yes, transmissions/differentials/etc. use vents to prevent pressure differences across their seals, to prevent leaks and seal popping. Besides temperature, altitude changes could also create pressure changes.
Nowadays, vents with membranes (such as gore-tex) can be used to allow air through while blocking liquids.
This is the vent on the Muncie:
It is a simple plastic push-in cap.
The hole in which the vent is pressed into does not have a direct view of the gears; the vent hole intersects an angled hole, which (from memory) leads to the shifter shaft area.
[This message has been edited by pmbrunelle (edited 05-22-2025).]
