Servo Issue

[Tayter]

Gents and ladies

Had the lugs break off my Ace DS1015 servo at the weekend in my XB4. The case was old and one of the lugs was already missing. Anyway changed the case from and old broken servo and under power everything works smoothly. When I switch off power the servo cannot be turned by hand, checked to see if it is a tight case, by trying to turn with servo arm with the case off, but still tight, checked gears and a missing tooth, so replaced all gears, but still tight. Anyone have any more ideas or will I need a new servo?,

Cant think of anything else it can be? any experts out there can help?

Steve Taylor