Like posted before. The only things you're looking at here are U-joint, diff, or bearing. "Helicopter" noise on one side of the car leads me to belive it's an axle bearing. I'd put money on it. But like the guys already said, there's no reason an 8.8 "goes bad" under normal use. Fluid level has to be low, so we need to find out WHY. Fix the bearing, then fix the "WHY", and you're good to go.
And I'll bet you a donut that the Helicopter is a "COBRA"! hehehehehhe
