There's a weep hole at the bottom of the adapter housing. If the rear seal on the transmission or the input seal on the transfer case leaks, it weeps out this hole. Gear lube indicates the transfer case.

Another possibility is the t-case shifter assembly could be leaking higher up on the t-case and running down the front of the t-case.

Cleaning it up and watching it is a good thing to start with. <img src="/forums/images/graemlins/kewl.gif" alt="" />

'06 Dakota QC 4.7 6sp 4x4
'88 Mighty Max
'77 KZ1000 fun old bike