Rear Diff Leak

If it’s actually the Drain Plug leaking, then tighten the 3rd member nuts will not help.
Is there a change the leak is coming from further up?

 

I can’t quite pinpoint exactly where the leak is starting from, but there is typically a drop of oil hanging off the drain plug as you can see in the picture. Now, whether or not it’s actually starting from higher up and dripping down, I’m not sure.

 

FWIW, 18 ft/lbs looks to be correct.
It’s up to you whether you on how tight to get them.
I’d probably just check them by hand, while keeping in mind that 18 ft/lbs isn’t a lot.

 

Get a can of brake parts cleaner and wash it down.
You should be able to tell where the leak is once the diff is good and clean.

 

You really need to wipe that part of the diff clean and monitor daily so you know where the oil is coming from.

 

I agree with the folks who suggested confirm it is tightened to spec with a torque wrench first. Back it off a turn and re-tighten to spec. Torque wrenches can get out of adjustment: it has happened to me. Maybe borrow one from a friend to confirm. I have been a shade-tree mechanic since I was a teen and was someone who was always worried about over tightening bolts etc and didn't over-do it with muscle power, only to find leaks later because I was off when I re-checked with a borrowed torque wrench. My Dad taught me to leave my thumb off the ratchet when tightening things to avoid over-tightening and stripping the threads. He is a member of "The Greatest Generation" and did a lot of side of the road field repairs. For him, a drip was less serious than a stripped bolt in a critical spot. Cars leaked a lot in his day anyway and he didn't really stress out over it: "keeps the rust down".