Oil leak between motor and gearbox, already changed rear main and upper oil pan seals SR20

[180sxdan]

I bought a 180SX recently with an SR20DET and noticed a leak between the motor and gearbox.
First off I thought it was the rear main seal so I changed it out and resealed the retainer.
Then it was still leaking so I looked back at a photo I took of the rear of the motor and it looked like it was leaking from the upper oil pan so I took off both oil pans and resealed them both. Now I've gone for another drive and it's still leaking! I'm not sure what it could be leaking from.

It's not gearbox oil because the level is full and gbox oil smells awful, definitely don't smell that when I smell the oil on the bellhousing. I had put in a new rocker rover gasket, I checked and it's not leaking from up there.
Any ideas? I'm stumped.

Here are some photos I took from the back of the motor when I had the gearbox off to change the rear main the first time (which clearly wasn't leaking to begin with).





Photos of the leak from both sides, it's accumulating towards one side because I have the car jacked up on one side.

[amc49]

That type of rear main seal holder can be tricky. You must have the seal opening perfectly centered to not leak the seal and having that the bottom edge has to be perfectly aligned side to side. Depending on how designed and carried out the bottom edge can be exactly in line with bottom of block but some end up being slightly past to get good crush on any gasket there. That would likely be based on the sealing method used there, whether it was gasket material or simple RTV, which usually needs a zero gap there. If RTV the surfaces must absolutely be bone dry or you WILL be doing it again.

You use a tight good straight edge to check the bottom flat once the seal is in place, the seal can serve as the centering tool the OEM uses there but the pan must be backed off enough to be able to establish any high to crush more there. With pan up tight too you lose crush and the leak even if both sides are dead level with each other.

The seal hole centered on the crank determines which way the bottom flat ends up at. Too far down or dead even. Too far down but not needed and then pan itself leaks because it gets held up. Up to you to figure out what gives there.

If so far the seal itself since replaced has not leaked then it may help to run the pan to holder bolts up first before the holder to block, it may pull seal out of center but they can stand .005" out of round before they begin to leak. When I do one I do that but only partway, you don't want the pan to holder bolts so tight that the holder to block ones cannot pull the holder up tight that way either. It's a sneak up on the tightening in both planes sort of thing. If you tighten up either set fully before the other gets tightened at all you have likely screwed up there.