you'll have to remove the cover from that side and check, the seal behind the stator is the cankseal, that wont be leaking as you'd notice it in terms of engine performance so it will either be the selector shaft oil seal, the driven shaft oil seal, the clutch actator oil seal or a slight (as in non existant) chance the gear position sensor o ring has had it. i'm pretty sure as in 99% sure they could all be changed with no disassembly to the engine other than removing the oil. as i said remove the cover and check