I have a 1997 GMC Sierra 1500 and keep my transfer case filled up to the bottom of the fill hole to the point it will leak out when you unscrew the fill plug. I have done it this way since it was new. I just flushed the fluid and filled it back up with fresh ATF and now the fluid is seeping out the fill plug. It leaks just enough that a new drop will form in a few days. The plug is tight and I dont know how it is leaking/seeping??? It has never done this before. Any ideas? Would plumbers tape stop it from leaking out? Here is a picture of how much seeps out in a day and eventually it will start running down and dripping.