- 1 printed bearing cage (I used ABS, but any hard plastic should work as long as your printer is dialed in and you use grease that’s safe for the plastic) - the 5 bearing balls from the original bearing - the 2 washers from the original bearing - external washer and clip from the bottom of the office chair - lithium or silicone grease (recommended) Repair Instructions Flip the chair upside down, ideally on a soft surface to avoid scratches Remove the clip and external washer from the bottom of the lift cylinder (be sure to keep the washers organized as there are three different sizes involved) Carefully lift the bottom half of the chair (including the black metal cover of the gas cylinder) off of the top half Remove the parts of the thrust bearing from the end of the gas lift rod (1 larger washer, the bearing cage with balls, and 1 smaller washer). These may be stuck inside the bottom cover and need a long tool to remove. Remove the bearing balls from the original cage and insert them into the printed replacement (you may need pliers to squeeze the balls into the new cage) (optional, but recommended) Liberally apply grease to both sides of the new bearing cage, covering the inner and outer edges and the balls themselves Reassemble the chair the same way you disassembled it (if a thick rubber washer/bumper fell out of the cylinder, it should go back onto the rod before any of the bearing parts) Spin the chair around to test the repaired bearing. If there is any friction, you not have applied enough grease or there may be a defect on the printed piece from the printing process. In my case, the chair spun with even less friction than it did when new, even with my weight on it. A diagram for how the assembly should look can be found here