Open Plug Hole in Flywheel Housing

[Glennman]

1974 MCI MC-8 8V71. I am in the process of changing my oil, and I find this open threaded hole (1" pipe plug) about 3" and 45 deg. below the lower starter mounting bolt. My Detroit manual shows this hole, but there is no reference to it. It appears to be only an inspection hole, but it seems like it would have a plug in it. I can see the flywheel through the hole.

With that being said, there is also a 3/4" plug at the bottom of the flywheel housing. What should I expect to see if I remove it??? If there is oil in it, would that indicate that the rear main seal is leaking? I haven't removed it yet, and don't know that I even need to.

Again, thanks all! Glennman

[bevans6]

It might be a hole to access torque converter bolts, if you have an automatic transmission.  Otherwise, no big deal.

[luvrbus]

The hole below the starter is to remove the torque converter bolts as Brian posted most are plugged ,the bottom is for oil drains it should not be plugged ,some sellers plug the bottom hole so if you have a rear main seal leaking or with a automatic the front transmission seal leaking remove it and see it should be dry