rearend noise

[rcockerille]

ran over something in the road that hit the car somewhere around the drive shaft or diff.:cry::cry::cry:
After that it began to make a growling noise when I would take off. Thought at first it was a wheel bearing but last night it started making noise really bad. Makes loud noise while driving also. not a consistant noise but enough to worry about. any sugesstions? any differentials for sale out there?:confused::confused::confused:
just read it could also be the drive shaft. if so id this big bucks like the diff?

[Progress]

There is a sticky called sounds from the rear explained. I would read that one.