View attachment 59288 I just replaced the fluid in my transfer case and after driving it, there is a leak out of a threaded hole in the advance adapters piece that connects the sm420 transmission to the d18 transfer case. I filled the transfer case until it seeped out the fill hole. The fluid level was much lower before I changed it, which would possibly explain why it wasn’t leaking before. Is there a special purpose for this hole that is leaking? A vent perhaps? Or should I just plug it? Assuming I should plug it, does anyone know the correct bolt size? Also, I replaced my transmission fluid about 3 weeks ago and I have smelled the fluid ever since while driving (but there is no leak). The shifter housing on the sm420 isn’t exactly the most air tight contraption, so I suspect I’m smelling it thru that. Is it normal to smell the fluid while driving?