Need Help 2000 explorer roaring noise?????????

Hey guys I was wonding if any of you could help me with a problem i am having with my explorer? it has a roaring noise coming from the front end of the vehicle, it starts at about 20-25 mph and stays at the same volume until i hit about 55, i took it to the dealer and they said they could not diagnose it and that they would have to keep the car and tearit down and charge me 600$ just to tell me whats wrong with. THe oil seal on the front differental is leaking im not sure but i really hope this might be the problem, they said it could be the axles,wheel bearings going bad also. any help i would really appreciate thanks

One thing you should check is the wear on the tires. You may also want to rotate the tires front to rear, and make sure they are properly inflated. If the noise changes when moving the tires from front to rear, then the tires may be the source of the noise.

Otherwise, yeah, differential, wheel bearings, axle bearings, pinion gear, etc. could be the source.

-Rod

another good idea would be to lift the vehicle,preferably on a lift, and if you do it with jacks stands make sure that the vehicle is securely lifted and all 4 wheels are off the ground(by this i mean be absolutely sure its safe, safety is always first) then place it on 4x4 and run it in drive until the noise is present then with a mechanics stethescope try to find where exactly the noise is coming from. when performing this kind of test always stick to common sense(i.e. stay away from the tires)