[jrelliott]

The shims are for taking up the slack between the teeth of steering sector shaft and worm gear at the end of steering column. You want as little play as possible without binding. You install or reduce the number of shims to get the least amount of play between the steering gear and sector shaft. Takes a bit of installing and removing to get this correct. The closer you get these two the less play in the steering wheel. The O ring goes between the sector shaft and the frame. Make sure everything is clean before installing the tube with the nut at the end. A little locktite on the threads of the tube will stop any leaks of oil out of the unit into the light switch.