spt

Hi agian, 1998 f150 2wd axle code 19 3.55 and a dana read end. Code 19 is suspose to be conventional non-positraction differential. Today I was fooling in the country and trying to climb a hill and spun out. When I backed down I noticed where I spun out both tires dug in and where spinning. So I found a stretch of gravel road not being used and had my friend get out and watch my back tires to see if both would spin. I hit the throttle and both rear tires spun the whole time I put the throttle down. Does a conventional non-positraction differential do this on loose stuff but maybe not on pavement? I have not tried doing a burn out on pavement yet. Thanks