Originally Posted by FullThrottle02
It is the differential vent hose. It doesn't connect to anything. It should have a little cap on the end. No need to worry.
I dont think I've ever noticed a rear one with a cap before, of course, I've never really paid that close of attention to it...mine never had one and still doesn't.
Not a cap aka a plug, but a 'floating' cap that allows full breathability. I've got those on my front axle and my tcase.