The sleeve looks like someone cut the bottom 1/3rd off of a Coke can. One side has a lip on it. I installed mine by putting the sleeve on as far as I could with hand strength (which is pretty strong on my right hand, <img src="/forums/images/graemlins/butwiggle.gif" alt="" /> ) and then I sat the crank pulley on the flat garage floor (sleeve side down) and then put a board on top of the pulley, and hammered the poop out of it until it slid on all the way.