I dont know if this is the same issue, but I have a 2007 and my tranny at 35 to 40mph will shift into 5th and I will get a droning sound from it. If I give it a little gas it gets louder until the rpms get higher. At 45+ I do not have any noise. It has done this since I bought it but never worried about it cause I have not had any problems. I just ran across this thread and was wondering if it is the same thing I am experiencing.