No it is just a vent. Its purpose is to allow the air inside the diff, that expands/contracts as the diff warms up/cools down, to move freely into and out of the diff. If there were no vent, as the air expanded during operation (heating up) it would end up pushing past seals which would push out gear oil as well.

 

. so i just leave it and it does its thing eh? sounds good. Thanks man,

 

Wow I learned something, now I know what the tube that ends right there is. I always figured it was for some option that wasn't in mine or something.