The original sprocket slipped into the seal almost too easily and there was slight wear on the hub of the sprocket. So I swapped it out for a 22 tooth sprocket to help the Ironhead on highway speeds. I noticed it was a way tighter fit on the seal so I forsure thought that was the culprit. But she's still leaking! ALOT. Almost a 2in circle on the ground within a few minutes when parked.
It's primary fluid so i don't know any other places it really can be coming from.

Also I just recently changed primary fluid. maybe I could have overfilled? add a quart as recommended.

 

I installed the nut Phil13 recommend which helped but she is still leaking. After further inspection it looks like this area is the culprit. I believe it's a stud that goes into the primary but im not sure. Any ideas if it can get removed and press a new one on? or is it suppose to be threaded? some insight would be appreciated!

 

It has been a while since I have been in there, but I believe that that hole goes right through into the transmission cavity, it is threaded and the bolt can be exactly 1 inch long. I do not know the other dimensions of the bolt.
Remove what is there, clean up, take good pics and inspect

 

Breezy Knee,
Was just browsing the site and noticed your post. I had an oil leak issue that was driving me crazy. Not because of the leak but not knowing where it was coming from. Because everything is so tightly packed on a bike, it's hard to find a leak sometimes. Thought it was the oil lines since they appeared to be original. The lines were cracked and real crappy and were a pain to run perfectly but took care of it. Still had a small puddle under the bike whether I ran the bike or not.
Turned out to be the lower bracket on the back of the oil tank . The weld from the factory had a small pinhole. I think it was leaking since it left the dealer. A good sanding and epoxy- no more leak !!!!

 

I wonder what that threaded hole was for