Motor shaft came through the endbell on CC 2200kv. Why?

Should have mentioned that the motor comes off the track after a 20 minute main at 170 degrees at the hottest location, cooler on other parts.

I run 4S batteries and have to do a battery swap to make the 20 minutes. Seems like once the motor gets to its peak temp, it stays there. I get the same final temp during qualifiers too.

ben