i've been reading and searching about converting my 89 3 piece to a 96+ 2 piece, (not the entire axle, just the shafts). but im curious, what was the thinking behind the cad system and what is different in the 2 piece set up?

i've read about how to do the swap. i want to know why the factory made the change.

 

The CAD has a 2-piece inner axle shaft that has a slip-joint to connect the 2 shaft pieces, and it was a weak link. either with something on the 'vacuum' side going out or the actual slip joint inside the axle not being strong enough. That's why the change. I actually did a swap on an earlier 'version' of my jeep, upgraded to chromolly's as well. I had thought the CAD was at least a good idea in that I theoretically could put a locker in, put a cable disconnect for the CAD and still be able to 'disengage' when I was wheeling and needed to turn tight. - Didn't last, that's why I did the upgrade then. 'course that led to more upgrades again...

 

The CAD increases fuel mileage. New trucks still use them. Less wear and tear blah blah. Chryco stopped using them because of higher production costs.