Everything in this picture:
http://www3.towerhobbies.com/cgi-bin...?&I=LXPCY0&P=7
The smaller bevel gears are the ones that shatter, while the pinions will break off at the hole in the shaft. HPI has some new, hardened pinions, and I haven't broken one of those yet - today was my fourth broken differential, two deaths by pinion and two deaths by bevel gear.
All this from a Feigao 9L.