Hey everyone, new person here and am looking for advice. I heard a loud chattering noise, like a flag flapping in the wind but loud. noticed it at high speeds only but throughout the day noticed it at lower and lower speed Looking under my truck, I found a lot of grease at the rear section of my front prop shaft kind of close to the Tcase. i didn't know a drive axle could make that noise if that is my problem. Any suggestions?