Let me say that I am not mechanically inclined so my question may seem stupid so please bare with me. I have an early MY99, 7.3L, F350. underneath the truck to the rear and directly behind the oil pan drain plug and to the front of the transmission pan drain is a small opening (kind of half moon shaped) that has fluid leaking from it. Can anyone tell me what this is and where the fluid may be coming from? Thanks in advance for helping a novice.