Neil G

Thank you! I'll go and check the vent tube. I'll drain some more oil as well, like open the fill plug and let it drain until it stops.

It has 113+ kilometers (I'm in Canada so it km). It's filled I think. I opened the fill plug again and it started dripping oil. I noticed when I opened the fill plug, there was a Sssshhhhhhhh sound like air coming out from the fill plug. Could it be the vent is clogged or maybe it's over filled?

I proceed to change the front diff fluid. I put in Mobil Delvac 1 Synthetic 75w90 oil. The front diff is now whining. Is synthetic oil not compatible with it? I read somewhere that a vent connector needs to be replaced if using synthetic oil. It was for older model though so not sure if the 2014 model is the same?

I crawled under my truck today and found there's some leaks along the front diff line. I'm not sure what it is. Can anyone please help me identify what it is. It's the small yellow part in the picture. The front diff itself is also kind of wet around the fill plug and drain plug area but no drip. Just like damp wet. 2014 Sierra 1500 SLT 4WD Thank you!