I have a 07 mercury mountaineer that makes a roaring noise and vibrates when driving 55-60 mph or higher. We have replaced the tie rods, axle, wheel bearings, rotors and pads, and got it it realigned and it still does it! We did rotate the tires and it didn't help. We looked it over underneath and everything looks fine and acts fine. I am lost on what it could be!

 

Set Tire Pressures to factory specs -- Buy and use a Digital Tire Gauge -- NEVER use pencil-type tire gauge !!
Have wheels balanced -- low-profile weights -- COMPUTER balancing ONLY !!
MUST use COMPUTER wheel alignment -- with PRINT-OUT !!
Have alignment technician set Caster, Camber, and Toe at the NOMINAL setting.
Wheel alignment and wheel balancing is critical -- accuracy is important.
Your vehicle will ride, handle, steer, and stop better with correct wheel alignment and balancing.
Those expensive Tires will last MUCH longer, too --
Spend a few dollars up front on a computerized wheel alignment (with print-out), and spin-balancing --
When done properly, your vehicle will respond like brand-new, and you'll avoid rapid tire wear.

 

I did end up bringing the mountaineer in for an alignment and balance the tires now it vibrates in town but it feels like its coming from the back now. I'm starting to hate this truck

 

My fix was rear arms bars and hub assembly. If those bushings go out it will growl like hell.