i have a 96 2500 and the drive shaft decided to come apart on me.... hope the picture worked but if not its the part going to the front diff. and it seem to be able to slide back together but i dont know....it happened when my U-joint came loose

 

^no pics in your post, but see if this helps any.
if your double carden joints messed up and you don't want to rebuild the ball, i think you can buy one already rebuilt.

http://www.pavementsucks.com/tech-article-16.html

 

it dont seem to be that but im not an expert its like i pipe part with threaded insides the went on the threaded driveshaft