My '03 4WD Eddie Bauer Expedition has 38K gentle miles on her.
Recently, the front end started to make a low frequency groaning sound that corresponds with vehicle speed. (One "grrr" for each turn of the wheel.)
I rotated the tires - no change.

I checked the front end, and there is a very small leak in the seal.
Brought it to my local mechanic, put it up on the lift, and the fluid reservoir was full. Pulling the front end apart is an expensive proposition and neither of us can really clearly identify the exact source of the noise.

Any ideas? Suggestions?
Where would I find information regarding any factory notices on this?

 

FOLLOW UP:
Now I have egg on my face.......I rotated the tires again, and the lumpy noise went to the rear of the car. Turns out that the tires are bad. Only 38K on them, but they are 6+ years old and they show signs of dry rot. I have maintained them well; with balancing and pressure checks regularly, but I now have 3 opinions (2 mechanics and a Ford dealer) that say I need to replace them....
The OEM tires were Continental's. I'm getting BF Goodrich replacements at Costco for about $160/tire with tax, road hazard protection and lifetime balancing and rotation. I couldn't do better on price at tire rack.
Live and learn.........

 

Glad you got it figured out..

I ran the OEM BF Goodrich LT's on my 05 F-250 for close to 85,000 miles and they still had some 'very decent' tread left but were starting to show some side wall cracking.. I've seen the same tire with only 30-40K starting to crack and seems to affect only the RW lettering sides only.. I tow very heavy on a semi regular basis and the BF's have been great for ride, service life, and wear well without constant rotations.. The last set I bought I was going to go a tad larger and more aggressive pattern, but decided to go with the original size/brand tires since they were trouble free, and would have certainly run to 100K if I had run them under normal loads or commuting.. The Continentals on the SD's never made it that far..

Going to just watch the 'weeping' seal?