Regarding the Teflon "sleeve" hinge pin issue, I offer another opinion.. Having had a vibration problem with two 235's, the errant hinge on both was the outboard left hinge on the horizontal stablizer.  On mine, I replaced the hinge entirely, on the other the owner had gotten the teflon sleeve hinge pin and wanted to try it..  This installation was loose at  the next annual, and the hinge replaced..  Coinsidentially, both A/C had a vibration problem which went away with a new hinge, but will perhaps reoccur again .. Regards &Happy Newe years to you all..   Don Skeele    235/320   N320J