Possible problem?

Update from last night.

They crawled over the car from above and below with a stethescope etc

Noise is definately from the box from just in front of the 'pan/sump' on the bottom. I'm guessing thats front diff or input shaft bearing thats likely to be on its way then

Anyone know the insides of these boxes care to comment on whats in that area?

Here's hoping the warranty is rock solid then............