What Kind of
Transfer Case ?
Also, forgive the "not meant to be" insulting question..., Did you lock in the front hubs?
Could be in the
Transfer Case , Driveshaft, or Front Diff...
So what i would do is put the t case in 4x4, but unlock the hubs (so they are free and forward momentum does not cause the drive shaft to turn), and either on jacks or have a buddy watch front drive shaft (without running him over
) and see if it turns... If so, prob in the front diff.
Note if you put on jackstands, you can lock the hubs to check whole system.
Other Ideas: Maybe the shift lever linkage?
You said you just changed the chain I believe, forgive another not meant to be insulting question, sure you got everything back together right?
Never done one myself, so not sure how involved / deep in there it is...
Hope you get it figured out man!
~ JR