My 2003 EB 4x4 is making strange noises from the front end. This is my second 03 so I knew something was up, I have a humming noise coming from the front end, it starts at about 43 mph and goes away just past 45mph. The noise is only there under power, if I lift off the gas it quits. I know it's not the tires as the were replaced last week and the noise didn't change. I had a friend that is a mechanic drive it and he suggested that it was the left front hub as you could also feel a slight vibration in the floor board and in the steering wheel. I replaced the hub and it does feel smoother but the noise is still there.
Now today on my way home from work I noticed a rattling noise, almost sounds like an exhaust heat shield rattling. It is around 30mph and quits passed that speed, after riding with my wife and listening out the windows it is clearly coming from the right front. If I turn on AWD or 4X4 the noise stops, but now even in AWD the steering has the feel of being locked in to 4X4.
I know this could probably be a million things, but was hoping someone has had similar experiences and could help cut down the possibilities. I think I definitely need a right front hub, but wanted to know what everyone else thought. Thanks - and sorry for the lengthy post!

 

Any ideas?

 

as your friend mentioned, i would start @ the r/f hub area since you mentioned the feeling of the 4x4 being engaged. when turning sharp does it feel again like the transfer case is engaged? check around the front axle shafts as well. keep us posted!

 

OK, I have replaced both front hubs now, and still having the same problems. Today as I was driving in 2wd setting I could tell that the rattling noise seems to be the front hubs wanting to engage, because I would here them locking in once in a while and could feel it in the steering. Same deal though it only does it under acceleration and right at 30mph. I honestly have no idea how or what engages the front hubs so I don't know where to start. I did notice that when the truck is jacked up in the front and I turn the front tire everything turns, meaning the front drive shaft turns. I thought that was odd, but I checked a friends Expedition and his did the same thing - so I'm not sure what makes the hubs engage, I assume vacuum - but again I'm not sure. Anyone have any ideas on what I need to do?? Also, can someone explain how this system works? thanks -Again!