This gap is at the front of the transmission where it mates with the engine (as seen from below).
Does it have a name?
Am I missing a plug for this hole?
Any ideas why it would be dripping fluid?
Please advise. Thanks!

can you identify if it's engine oil or transmission oil?

I mean, the real problem here is that you have too few leaks by the look of it. Get some road dust and half a quart of oil smeared across there and you won't even notice something like that.

So true! My mistake, of course, is cleaning the undercarriage ))

Both engine/transmission oil recently changed so both appear very similar. I am certain it is not coolant fluid )

Flywheel seal, or transmission main shaft seal, transmission oil has a very distinctive smell, open the transmission fill, put in your finger, bring out a dab of oil, smell that, use a different finger for the leak, smell that, different or the same, you have your answer.

Either way, you have a leak that will require removing the transmission. At a minimum. I would bite the bullet and remove the drivetrain. Beware the onset of project creep.

Exactly, tranny oil is stinky, engine oil not so

How bad is she leaking?

Your friction disc can be ruined by oil, not to mention the potential for slipping. Did you use synthetic oil during the changes? That could had led to the problem.

How much is it dripping, I'm not sure i would do anything yet. Mark

sometimes its hard to smell the trans fluid. You can add a dye, get it from autozone or other favorite local parts place along with the UV light . I had a similar issue not long ago, was not sure as i had just put the transmission back in after putting a new rear main seal in the engine, and after a couple months noticed a small drip here so i put dye in the trans fluid(suspecting this due to just putting new RMS on motor) . if you suspect oil, put the dye in the motor oil and run it for a few hours and recheck with UV light.
- as said by others, if the oil is leaking from the rear main seal it will get on the clutch and make a mess of it - when you pull it you will be able to see if it is leaking from the trans or the motor. - or both - thats possible too.

What is the history of the motor? how many miles, how long have you owned it?

the hole is there so that you can see the flywheel for timing, dont plug it.

if the car sits for long long periods or sat for years, the seals will dry , deteriorate and leak.

You can pull the transmission and leave the motor in, but i have found its easier to just pull them all as one unit.

If you have not done this, there are good how-to instructions on Pelican Parts website, with pictures.

Good luck

Phil

Are you actually getting a drip of fluid on the ground or are you just observing the blackness on the case below the hole? If there is nothing on the ground under the car I wouldn't worry about it, above that hole is your clutch so there will always be some level of black dust existing there.

If you are getting liquid on the ground then its either the trany or engine seal there.

"the hole is there so that you can see the flywheel for timing, dont plug it."

I've never heard of a timing window on the bottom of the engine. Just what timing mark on the flywheel do you use?
I believe it is for ventilation and a liquid drain, as you are seeing with engine/trans oil.

There is often a TDC mark on the edge of the flywheel. It shows TDC for #1 and #3 through the notch on top of the transmission bellhousing, and TDC #2 and #4 through the notch on the bottom of the bellhousing shown here.

I don't know if that was its intended use, though.

--DD

Sure makes valve adjustments a lot easier having a window there

Not 'leaking' nor leaving a puddle ... more like 'dripping' a few drops ... noticed after I started to clean the undercarriage.

Not 'leaking' nor leaving a puddle ... more like 'dripping' a few drops ... noticed after I started to clean the undercarriage ... not terribly concerned yet as it may be left over gunk )

Motor rebuild ten years ago with about 15K on it now. Was stored for a few years with monthly starts and short drives. Not 'leaking' nor leaving a puddle ... more like 'dripping' a few drops ... noticed after I started to clean the undercarriage. After wiping everything off again, let it sit for a few hours...no drips. Started and idled for 30 minutes, then let sit over night...no drips. Its raining today (we don't go out in the rain). Tomorrow is a slow speed tour of the neighborhood (don't want any blow back) followed by another overnight sit to see what, if anything drips. Thanks for your input!

100%, without a doubt, no debate, you have a leak on your rear main seal. A common wear item. If it was the transmission seal, you would see the fluid follow the path of the bell housing, not on the engine case.

Sounds like the voice of experience (which I lack regarding this issue). Since I have only small drips, any thoughts on trying a rear main sealer (thinking Blue Devil)? Please advise. Thanks!

No way on the goo. The seal will only leak more as it wears. It’s a pretty straightforward job and can be done with the engine in the car as long as you support the engine while the transmission is out.
https://youtu.be/o1sDHWxTOxk

I do my valve adjusts under the car using that window. I put a mark 180 out from the TDC mark and use each one.

--DD