BAD noise, hoping its CV shaft

[SX APPEAL]

91 240sx 5spd, has 300zx LSD w/ 5 bolt CV shafts. This just started today, it was a clunking type sound coming from the left rear. Over the course of an hour it went from low clunking to roaring, growling, and vibrating the whole car at anything over 35-40mph. It only does it when decelerating or coasting/maintaining speed. As soon as I start to accelerate the noise and vibration go away. Please tell me its the CV shaft, if its not I need to come up with a new plan. thanks

[rogoman]

Looks like you may have answered your question. What generally happens to CV joint failures is that the dust boot cracks and then the lubricant dries up.

If the CV joint is OK, then check the wheel bearings.