manual transmission leak

Anyone have any idea what this leak could be? Appears to be from the rear of the transmission and front of the transfer case. (98 TJ 4.0 with Ax-15 and np231 with 98k) The four bolts on the transmission mount are always a little wet. However the four bolts that are accessible from underneath...

4.0 5 speed, had the transmission rebuilt 2 years ago … been changing gears no problem but a leak has developed. Not the engine oil, I check it and it’s never low. What is your best guess as to the leak: transfer case or transmission? Smells like gear oil to me. TIA