Noise from rear when accelerating

[keiths]

Don't know if this noise is diff, driveshaft or wheelbearing related, but when I accelerate there is a deepish booming type of noise (not exhaust!) that is coming from the back of the car, it feels like its from the left side. I am assuming its a U/J on the way out, but as the diff seems a little noisy at most speeds I am a bit worried it might be more serious. Any suggestions on how I can check what it might be, before I go to a dealer with it?

[KeithS]

I think I will get it checked pronto, as for the sound barrier..... I'm working on it