2003 Jeep Laredo Problem

Hey guys, I am in need of some serious help for my Jeep. I have a 2003 Jeep Grand Cherokee Laredo 4WD 6-cyl with about 130k on it. About 2 months ago we were driving back from a haunted house thing and while on the highway one of the gears blew out in the front differential. Got back to my friends garage and we had to go buy the parts to replace. Drove back home and it was still making a growling noise but fainter. We looked at it the next weekend and found I needed a wheel bearing on the driver front. We fixed this and it was fine while driving it home that night. However, this whole past week driving to and from work it has been making a weird noise from the front. When I turn it on there is no noise but when I am backing out of my spot there is a little grinding noise until I put it in drive. Then I start accelerating and there will be no noticeable noise. As soon as I hit about 25mph (and anything over) there is a fluttering sound that is like a quick "whomp-whomp-whomp" noise. When I press the brakes without coming to a slow gradual speed there is a low grinding noise that sounds like it is coming from the front left-middle. I cannot hear this noise when I roll my window down and stick my head out. Had my buddy check the transfer case, rotors, brake pads, cv axle. Everything looks like it should and even he is becoming stumped.