Automatic 3VZE leaking ATF

Hey all, Ive had my automatic 89 v6 runner for a few weeks now and while working on other things mainly interior cleaning, I have noticed a leak from what i believe is the transfer case. Pics attached, it seems to me that there is ATF leaking from the knurled fitting on the side, not only that but moving it around it is clearly loose to some degree. Is this supposed to be a swiveling fitting? Does it need to just be tightened a little more or is there something more serious ahead.

As far as unsavory functions of the trans go it gives me a clunk when shifting into reverse (always stationary) but it is noticeable and takes a second or three to actually move into reverse gear. Also if I choose to floor it, say getting on the freeway, gives me a big clunk when upshifting coming out of high RPM's from the gear below. All 4x4 functions operate perfectly fine with no weird noises. I assumed these are just 30 something year old, 230k automatic transmission noises but I could be wrong.

If anyone's had this issue before fill me in on what might be the culprit. If this is a situation where its best to take it to a transmission shop instead of doing the job in my garage at home, let me know if anyone has any input on that too.

 

ATF leak chasing update: took a chance at just taking off the line it seems to be leaking from and its clearly the speedo drive cable. Also has a visibly old and not working o ring so I will be replacing that asap. I do not yet have a part number so if anyone has that on hand I'd appreciate it.

While down there I also located other things I could likely get done soon, seems that most of the oily mess is coming from the drain pan seals on both the tcase and the transmission themselves. The only reason I think that over output seals is that the messes only start below those points and doesn't seem to be getting flung around the underbody very much.

There was also some heavy epoxy over the seam on the low side of the tcase in this last pic. Not sure where to go about that except keep an eye on it to see if it leaks. Seems to be slightly damaged underneath it all from what I can tell after picking some off but not too terribly so, looks to be some ground away material and the epoxy is doing its job I guess.