I bought one of the hv-300 (or something) turnigy servos for my crawler. Worked great for about 5 runs. Then something started to slip. The motor in the servo would just keep spinning. So I tore it apart and found that the crown gears are all press fitted together. So I drilled a small hole on each side of the press fit and loc-tited two small grub screws in to keep that press fit from spinning. Now that servo is a beast. I have it running straight off my 3s lipo with no regulator. Super fast and torquey.
Chad
Indy