You have the correct drain plug, but since that is not the lowest point on the transfer case there is still some oil left in. The procedure to drain and refill the transfer case has been discussed here numerous times, you use search function to find it. Over time due to heat ect the oil level does get low on these and should hence be changes about every 25K miles

 

I know this is a super old thread, but, I cleaned up the area on the guide shaft seal nut, there was some old gunk, but did not look to be leaking. I replaced the the half shaft seal and re installed the TC. I pre-filled the TC and did some other work on the car.

I noticed a slight leak at the nut as the car sat on Jacks for a couple of weeks. The leak is extremely slight, nevertheless, it's weeping while the car has not run, so I expect this leak to worsen. I'm wondering if I should just try to tighten the nut or is there some sealant for that nut , just like the sealant indicated for the output nut on the prop-shaft. The picture on this thread shows the nut without a sealant on it. So I can either remove the nut, add sealant to it or tighten the nut and hope it stops the leak. Any recommendations?