1999 Suburban 2500 slipping

[phonix]

I have owned my 1999 Suburban 2500 4wd for close to a year now. When the vehicle is at operating temperature, the rear differntial seems to slip on sharp left or right turns. I have ignored it for close to 12000 miles, not knowing where the noise was coming from. But on a recent very wet day, in a parking garage, it was obvious the rear end was where the problem was. Any advise will be appreciated.

[Tuffdrvr88]

Try topping it off with gear oil and seeing if that helps at all. If it doesn't you may have broken a crush or something.