FinSailer - did you take the vertebrae pieces completely off the peduncle? You would have to remove the e-clips and use a punch to extract the .250 stainless shaft. I recently started making these vertebrae pieces out of delrin because some were complaining of the squeak of aluminum against aluminum and the wearing of the ano finish. The delrin produces a smooth action with no noise or wear. However, delrin is not nearly as strong as aluminum. Please take these pieces completely off - take the bushings out and insert the stainless steel rod or a screw driver and apply a torque to the hole as shown in this pic. Look for a crack that spreads when applying the torque.