So i just bought a 1982 VW Jetta Diesel. I believe it has the 1.6l. Ive been messing around under the hood checking things out. So far i put in a new radiator, done an oil change, and plugged in several sensors that have become unplugged over the years. I noticed a whole in the top of my transmission that looks like something is supposed to go there. I watched a few YouTube videos and on those cars it looks like a plug and hose are supposed to be there but i dont know what it does? Does anyone know what this is called? I haven't had any issues but i would like it to be fixed but i dont even know what part to ask for. I was thinkin i would replace it and get a tranny flush just to be sure nothing fell in. I love my old jetta and i plan on keeping it for awhile. Thank you for your knowledge.