GM has since released an updated model (but of course, no recall) that shortens the length of the shaft and puts a giant o-ring seal on each side of the shaft to prevent this from happening. The brown you see around the shaft and seals is corroded metal, slowly rusting away and destroying all the splines of the shafts. When they eventually failed, they took the flywheel with it as well.
Kazkorp is proud to offer this service and show pictures and details one of our customers CTS AWD that had them happen to them out of nowhere. We obtained a low mileage donor vehicle hit in the rear, and rebuilt the transfer case and transmission out of the donor with the updated parts, seals, gaskets, internals, and fluids.
IF YOU HAVE A 2008-2013 CTS AWD, rest assured this preventative maintenance will save you thousands down the road before it happens to you. There are reports all over the internet on this design flaw, so contact us for a cost effective solution that will become thousands of dollars in headaches down the road!