Looks like the rear main seal possibly. But not for sure unless you split the tranny/motor and check it out. A little leaking or seeping is normal with higher mileage motors but it will progressively get worse if it is. Normally judge it by how much your losing, a quart a month or longer isnt bad. But some folks are particular bout it.
01 TJ. Dana 30/44 4:88's, 4.0 5 speed, 38.5x15 Boggers on 15x10 Streetlocks, CAI, B&M short throw, Neoprene Covers, 4" RC, 3" BL, too much to list and building. >..<