Right where the side seam of the rear main seal housing meets the pan gasket. Where i have put a dab of silicone my entire life 😂. It's still required.

Was the leak at the outside of the gasket there, or around the nuts/studs?

6 VOLTS/POS. GRD. NW INDIANA

Just to update. I got this installed and had a massive leak. The instructions say "use no sealants" but you still need the two spots on the rear main seal housing. It's dry everywhere else. I would retorque after a couple heat cycles as well.

That's funny. I got a Jaguar transmission pan gasket as well. They did make it right, hopefully installing next week.

Ted Eaton recommended using a sealant on the stud threads that go into the retainer; otherwise, it would leak. Although it hasn't been that long, I think I might have used Loctite Blue. 

The OEM-type studs have interference-fit threads on the ends that screw into the retainer;I bought mine from Hill's Thunderbird. Initially, I thought that they didn't fit; they do, they just require a little more force but won't strip the aluminum retainer. Even though the interference-fit threads are supposed to provide a better seal, I still used sealant. 

By the way, Tim Hill is very helpful; needless to say, so is Ted Eaton.

So, I installed the oil pan (etc.) with the silicon gasket. Followed all the instructions to a ‘T’, BUT, ran into a quandary re. torquing the stud nuts. The builder had sealed the studs into the retainer with RTV. and there was enough left on the threads to load the torque specs. Couldn’t find any specific data that indicated whether the nuts get the same torque as the bolts either, so I just made sure the lock washers were flat, and then gave a little extra twist. The gasket ended up straight all the way around, except it creeped out about 1/32” at the rear. The gasket tech person suggests I should just loosen and re-torque everything.
At least, now I know how to use a claw-foot torque wrench attachment (pick-up tube to pump nut) 😁. Mummert’s installation video didn’t specify any thread sealer there, but I suspect some Permatex #3 wouldn’t hurt (?).

6 VOLTS/POS. GRD. NW INDIANA

They ARE sending me a free replacement, and don’t require I return the trans. gasket.
BTW:  Turns out, the package labels appear the same, but the text IS different. (I saw the words ‘oil pan gasket’ & ‘silicon’, and just didn’t notice the word ‘JAGUAR’). If anyone owns a ‘69-78 XJ16/12, they are welcome to it (?).

6 VOLTS/POS. GRD. NW INDIANA

I'm inclined to believe that they'll make it right. What vendors of classic/antique auto parts need to realize is that these vehicles aren't daily drivers; therefore, parts aren't necessarily used right away. I have new parts that were purchased several years ago and are still in boxes.

I ordered their oil pan gasket back in late ‘24, and just now got around to opening the package. Turns out, they sent me a trans. pan gasket by mistake! Packaging/instructions appear universal (NOT product specific), so just didn’t notice it’s smaller size. They are closed until after the holiday, but I’m curious to see if they will stiff me, since the return window has long elapsed. Stay tuned.

6 VOLTS/POS. GRD. NW INDIANA

👌