What is this Hose

[exp999]

Hope someone on this forum can help identify the hose for me. Saw the hose on the front end passenger side hanging down below the serpentine belt. There is a white cap on the end as shown. The other end connects to the front drive axle/transfer case. I don't see anything this connects to. Is it a venting hose and why so long?

First pic is the hose by the front and second is the connection to the front drive axle casing.

Vehicle is 1996 Xplorer, 4WD, XLT.

 

[windsors03cobra]

You are right it is a axle vent tube, its up high to keep it out of water and prevent contamination.

 

[exp999]

Thanks for confirming it's a vent tube.