Loud rumbling sound felt in console area when 4 wheel engaged

[jruppert]

I am in the process of searching for this issue but thought I would also post my problem and see what you guys come up with.

I have a 2004 5.4 Expedition and recently noticed that when the 4 wheel is engaged while on freeway there is a loud roaring or rumbling sound followed by a bad vibration. The vibration is felt in the console area under driver seat. When disengaging 4 wheel, it takes a while to do so. Sometimes I have to tap the brake and I can hear/feel it disengage.

Tires are all the same size and in excellent shape.

I am leaning towards u-joint in driveshaft but not sure if it could be a bearing somewhere. That is why I am asking.

What are your thoughts? Thanks

 

[bedrck46]

Is this something that just started or has it been an ongoing issue Check the fluids in the transfer case and front differential also check front wheel bearings

 

[jruppert]

To be completely honest, I have no idea how long it has been doing this. I know last winter it was very quiet. I have not driven the vehicle much and when I do I leave it in A4WD. We are in Michigan and the roads have been cruddy for the past month. My wife has been driving it in 4 wheel on the roads when they are covered. That is how I knew about it. Up until then I had no idea there was an issue. I will start by checking the fluids and go from there. Thanks

 

[bedrck46]

get the DVD I suggested it will give you a lot of information on the different systems and also help when you do have questions here on the forum

 

[jruppert]

Thanks for the suggestion. Will do..

 

[stamp11127]

My experience with 4wd has been with all mechanical systems. Don't know how the new systems will behave with the electronic goodies. I would pull the front drive shaft and go for an easy drive in 4wd. If the roaring sound isn't there it is time to look at the transfer case. Have a real good look at bearings and races.

 

[jruppert]

If you remove the driveshaft and drive in 4wd and noise goes away, couldn't the noise be coming from the u-joint in driveshaft? I guess the u-joint would probably not make a loud roaring sound though.