We must find the error to fix the problem not just bandage it. Well, the problem is not mainly in the gyro, but it is in the tail. First of all, you have to modify the tail for slop free. All you have to do is to use a permanent marker to mark the internal area, where it connects to the shaft, of the tail blade holder. Reassembly the tail blade, and turn a few turns. Use Dremel tool or Xacto knife to cut off (little by little) the area that lost marker until it is free of slop. That would help the servo much easier of controlling. Currently, I am using Futaba G-155 mechanical gyro with sensing turned half way down, and my T-rex is still extreme stable when hovering.