its has its fitted in the first place , you hold lever square to the hole in the box side but fully engaged in the slot in the rev idler then wind bolt to meet it ,the lever is threaded , when fully tightened you check lever is not to fully engaged to be tight on idler or too loose it can jump out, it may take a few attempts to get right because bolt is going through 2 threads box side and lever so how many threads appear through the box side before thread engages in to the lever is trial and error