05 V, 87K, Original rear end etc. When driving normally - low RPM's around town - no problems. If I do any more spirited starts, just get the RPM's up a little starting off in 1st gear - I get "The Whine". Sounds like it is the rear end - like it is coming from the floor board of the back seat or under the back seats. The whine tracks the speed of the tires, ie it does not vary with the speed of the engine RPM's. It remains up through all of the gears and does not end - Until I come to a complete stop, put the car in neutral, and sit for while like at a long red light. If I start off again in a calm manner without getting into the higher RPM's, the whine is gone. It seems to appear only when hitting high RPM's in 1st or 2nd gear - if i meander through 1st & 2nd then get on it in 3rd or 4th, it does not start to whine.
Is it about to blow? any ideas? Thanks for any info.

I'd recommend you read this thread again.

A lot of GTO and CTS-V owners have played around with different kinds of fluid, but a lot have had the noise go away (at least for a few thousand miles) by changing to Royal Purple, Amsoil, Mobil1 etc....

What 1Ags said.

TBSS's also had the whine from the rear. There was even a TSB on it, IIRC. The GM guys just added their GM additive. Most owners would switch to a better lube altogether and that would fix it.

I put 75w/140 Royal Purple in mine w the additive...still whined, but was a little quieter.

KICK YOUR WIFE/GIRLFRIEND OUT OF THE BACK SEAT.