Bearing gear 11t (Rotax max FR125)

Hi guys. I would like to know why my Teflon sleave moves after a little bit on my 11t gear of my rotax max, which causes a tightening of my clutch which no longer works well. There is an oring at the bottom according to the specifications, but since the sleave moves, it comes to tighten on the oring. The dealer told me that the part indicated in green had to go towards the outside of the gear, but I was unable to put it in if I do not put this part in first, inside, finding that it made more sense to marry the oring. In fds, I had to remove the oring for it to work well, advised by a mechanic, but this creates a looseness that I do not like. The oring is supposed to prevent the grease from the sleave from going into the clutch. I have a new clutch on my rotax max.