When reinstalling a Shimano freehub to a hub designed for use with disc brakes, the Shimano spacer should be fitted with the ridge towards the freehub body. Rim brake models do not require the spacer. Put the spacer into the freehub body, replace the axle in the freehub body, and place the threaded body spacer into the hub. Rin g leaf springs placing them into the space between the hub’s cone and the hub shell, then put the ratchet ring in place and finally the hub. The axle which has been passed again through the hub shell needs to be turned in order to connect the ratchet. A non drive side end cap should be installed on the needle bearing and tightened again using 17mm cone spanners.