Rumbling/humming nosie underneath?
 

In the last week, I have noticed a rumbling noise when decelerating.

Lets say i am in 5th gear (stick shift) and i am coming to a stop. I push in the clutch and shift to neutral. Meanwhile, underneath i hear a louder then normal noise. it sounds like a rumbling or a humming noise.

any ideas?

Is it only when the clutch is depressed, or when it is in neutral?

It could be the throw out bearing, but don't quote me on that. Some of them make a humming noise, while others make an all around clanging and banging noise.

only when it is in neutral, no banging here yet, justa humming noise and maybe slight vibration in brake pedal

ive come to notice it starts getting louder when i get to about 42 mph.

then coming back down, it quiets down when i get below 42 mph.

ideas?