I would take the roller off anyway, so you can get at the nut. 22mm I believe they all are on the linkage. 8mm under your finger for the roller with a 12mm nut. I have all the linkage apart on the 01 yz125. I need to buy another set of impacks though because I only have one 22mm socket. , and the swing arm one is deep. All the newer YZ's I have worked on have a jam 1/2 moon bolt and thats nice. Keep working on, you'll be fine.