Join Date: May 2016
Location: Woodinville, WA
Feedback: 0 reviews
A transfer case is pretty simple, there are no true consumable parts like clutches etc. Your biggest concerns would probably be the input/output shaft seals, and the chain stretching. The output shaft seals are not really any harder to change later than now so I'd just leave them and see how it is, swap them out if they leak. You just have to take off the output yoke which you can easily do with the case mounted in the vehicle. Might be worth swapping out the input shaft seal since it's a pain later as you'd have to drop the case. See how the input and output shafts feel, if the bearings are tight no need to change them, there should be a tiny amount of axial slop (I don't know the actual spec, but on the order of a small fraction of a millimeter), and zero radial slop. That is assuming the yokes are installed, there'd be huge axial slop without the front output yoke installed.
In conclusion, I'd change the input seal, see how the bearings feel, and if they feel good then run it.
JK has a pretty beefy transfer case, there's a pretty good chance everything is perfect, except the seals who knows, a seal is a seal and depends on how the vehicle was treated and what it was used for (wheeling mud holes is particularly terrible on shaft seals)