Funny metallic clink while shifting whats wrong?! Need Help.

Hey Everyone,

TLDR: Some oil seems to be leaking between transfer case and the transmission. '96 Toyota Tacoma with 200K miles, 3.4L V6, standard transmission. Funny clink that is distinguishable mostly when shifting into Reverse, 1st, and 2nd... but sometimes can even here it in 3rd. Has began to show itself over the last couple thousand miles or so. I checked fluid in transfer case and in transmission and it was at the fill line for both. Also they were both changed about 20K miles ago. WHERE IS THAT CLINK COMING FROM ERR???? and WHY does it seem like fluid is leaking between the two units? Is this common does this normally happen?

More info...

So here is the story, over the last couple thousand miles I started noticing a funny sound (sorry I know how ambiguous this is). It happens pretty much when shifting (usually around when I let out the clutch). The sound is metalicy, like a clink or a "ping" or something. When I crawled under the truck I noticed that there was fluid that seems to be looking form the top side of the tranny kind of right where the transfer case and transmission connect. Upon taking the shifter cover off I took a look in from the top and it really appears the fluid may be seeping out between the seem between those two units???

So questions I have are...
Does it seem like the seal between the transfer case and transmission could be suspect to degrading over time and busting a small leak?
Is the small ping I hear shifting related?
Am I causing damage driving this while trying to figure it out?

About 20 K ago I replaced the clutch, pilot bearing, throwout bearing. Everything went good on the change as far as I could tell... was the first one that I had done though

Any help would be great!
Thanks!