Hi Michael,
Thank for your response.I never crash this plane and also my landings is not hard. Funtana elevators is very lights also. In our flight site have 7 planes like this with same servo configuration. Funtana manufacturer design tail with this servos and i think his know what they do.
Another buddy report this failure to Hitec service and received a new top cover case. This servos was brought from Tower Hobbies and i don't know if them also have a 2 years warranty. I think also is a cover material failure or sub dimensioning in bearing top axle zone..Wall to thin.

Where i can order the top cover case ?

Dino