need help and possible causes and solutions to a problem ASAP due to warranty

[Skullcamaro]

For a while now I've noticed that sometimes, not every time that I reverse whether it's a turning reverse or going straight back reverse, there is a very strange and troublesome noise coming from the front end which I'm unable to pin down. The noise sounds very loud usually and is similar to tearing or grinding of metal pieces or a collision of something with another part of my car.
When it happens it is constant sound depending on how fast I reverse and it doesn't matter what speed I reverse at it still happens just the degree of noise and the noise level changes. It's just got me worried that something with the trans. is breaking or loose of the flywheel is damaged or something like that. This only happens when I go in reverse and does not always happen. Also I was thinking of possible problem with my suspension or or tires or steering components. Any help would be appreciated and I need to know ASAP just to be on the safe side especially since its driving me nuts not knowing what the noise is and if it's causing damage. Thanks in advance either email me at opt0tolerance@aol.com or post here. Thanks again.

[Fin]

When was the last time the trans & rear-diff were serviced?

[Skullcamaro]

It was serviced less then 6 months ago. A new rear diff. was put in around January or so and then I had it serviced around June/July time. It sounds like its coming from the front end or near the middle of the car. Any ideas? Thanks.

[Skullcamaro]

Any ideas? Anybody?