Here is some background info: 2007, I bought in 2009 with 9000 miles now háve 35050 miles. About a year or so I notice it was getting louder in rear end. But thought it was just road noise due to my tires and just ignored it. That is until recently. Then one day while at a stoplight I wanted to know at what point I would hear it or was it a constant noise. It begins at about 17mph and remains until I stop. It doesn't matter if I'm going 20mph or 75 mph, nor does it matter if I push the clutch in or it's out. It still sounds the same. The only way I know to descibe it would be to say, it sounds like the noise of an Ultrasound or perhaps metal against metal. It's not my brakes. Were I to make an educated guess, it's in the differential(sp) Pinion bearings? Or could it be coming from the wheels and could it be the wheel bearings? Is there any way I can find out for sure? Without taking her to the Ford service Dept? At first, I thought it could be the transmission but I just changed the fluid and it was totally free of any debris plus it shifts like butter and always has. Please any and all will be greatly appreciated!! Any " how to" as well! I thank you in advance!