spider gears

well I I finally got a good driveshaft under my dart thanks to this site. awesome by the way.i took my car for a ride today. ten twelve miles. did a pretty good burn out. all was fine till I went to turn right.all hell sounded sounded like it was breaking loose in my diff. babied it home.took it apart as soon as I got it in the shop. the spiders on my 8 3/4 chunk are locked up. I have never seen this before.it's a 489 case non posi of course.till this point when I would do a burn out it would turn both tires and was quiet. tody it only turned one tire and is noisey around corners. has anybody else had this issue