It's the nut that holds the trans sprocket on. It has a seal built into it that goes around the mainshaft. It is a band-aid for the leak between the mainshaft and 4th gear bushing.Dang. I am straight up highlighting my own ignorance, but what is a supernut? One with the plastic lock in the thread barrel? A set of two thin nuts? I cant figure this one out.
i think the same guy has an instruction vid on youtube.ill post if i can find it.The problem is that there is no positive seal too prevent oil leaking past the sprocket spacer in the main seal. Oil gets past the inside of the spacer and is free to leak out the splines where the sprocket mounts on the main drive gear. The super nut only seals one side of the sprocket and thus only one half of the leak. Saddlebagrail (Ray Dugay) who frequents the Shovelhead.us forum is a brilliant machinist and makes a very effective spacer with an "O" ring that cures once and for all this annoying leak.
I use an electric impact for motor sprockets and tranny sprockets and have never had a problem even with supernuts. They have enough to tourque it down, but not too much to where it will overtighten and rip out fine threads like on a tranny mainshaft. I wouldn't use and air impact on a bike.I am reading it as use a hand ratchet rather than an impact gun