Limited Slip Problem?

Sounds like 2 possible issues; the revving up with no moving (as I read your 1 symptom description) could be the trannie. OR, the splines into the differential are stripped off of one axle shaft, or some carrier gear teeth arae stipped. If you have a non-LSD (open) diff, then these would cause the slippage.

Not sure what you mean by 'hearing it first in the corners'....do you mean when the car is moving under power or starting from a stop in a corner? That could also be a sign of stripped splies on one axle shaft. Pull all of the fluid from the rear pumpkin with a suction gun and see if there are metal bits in it; especially get the stuff from the very bottom. Or, better yet, pull the pumpkin cover after sucking the old axle fluid out. If you find metal bits, pull both axle shafts and inspect the splines. (I would do that anyway; it is not hard.)

You could see stripped axle splines, or some sign of something spinning around on the axle splines; there should never be anything spinning on these splines; if so, and the splines are intact, then the matching splines on the side gear in the diff carrier are stripped out.

And without any damage to either splines, then the teeth on the side or small pinion gears could be stripped off; that you can see with the rear cover removed.