when i drive my 05 ss when ever i drive and let go of the gas the car makes a wierd sound that is very loud almost sounds like grinding but not quite it also makes the same sound when im on the highway at a constant speed my car got 156k on it with the original clutch it makes the a less intense sound when i and rolling at a faster speed but its louder with clutch engaged i thinking its jus cause the clutch on it way any thoughts or wheel bearing it also makes this loud thump sound when i go over bumps

 

The thumping noise is most likely the stabilizer bushings or the connecting arms I just replaced both and my noise over bumps is gone.

As far as the grinding it sounds like a wheel bearing but it's hard to tell, jack it up and spin each front wheel & see if you can feel a grind or noise, also shake the wheel while you have it jacked up to see if there is play in the bearing?

I have 05 also & I replaced both front bearings at about 90,000 miles mine made a humming noise and got worse the faster I went.

Is it on the drivers side or passenger side or can you tell with the windows down?

Look at your CV boots & make sure it's not a CV joint?