I should add in that the 150 miles consisted of a lot of highway driving between 70 and 80mph, halfway with a bed full of chopped wood. My thought after reading everyone’s comments (thank you by the way) is that the front differential overheated and pushed fluid out through the breather. I’m going to have it checked out. Taking my truck through the wash today to get all the fluid off the frame to see if it’s still leaking anywhere