eracingpro shafts

hi all...ye, but the shaft dont fall out of the cup, even after its bent. and its not too far in either pin is half way up the cup slot.
its when i tumble over front to rear, then hit outside of rim against the ground the arms give but the shaft cant so it just bends.

so why do i need to fit revo axle carriers to use these shafts? or do you mean the hubs, due to the lager inner bearing?

as traxxas call what i call an inner diff casing they call an axle carrier? but they also call the hubs axle carriers too so im confused by it all...
i trust u mean i need part 4334 for a 3905? yes i know these will have to be changed (i need new ones anyway)