If it's hitting blank spots on both wheels, there's a good chance it's the diff. If one wheel seems like it's a little less powerful than the other when you hit those spots, you have a bad CV axle on that side. You might jack it up on both sides, take the tires off, and have someone run the car with 1st gear engaged. Look at how the CV axle moves. If it moves in any irregular patterns or fails to move only on one side, it's that CV. If it's consistant on both sides, prolly a diff. Sounds like a CV with the sounds and all. Good luck man!
I ran a search already!
99 Ford Contour SVT - SOLD!!

'90 CRX Si, '98 Explorer V8, '98 Acura ITRally Co-Driver