After 9000 miles your going to have wear items to replace with sleds that are tuned… No surprised there, but if things are trued and balanced properly it goes a long ways toward longevity, not to mention getting things sealed properly without leaks… Sometimes we can create problems just by taking things apart that don’t need attention.. Other times we let things go too long and we create even more problems… The fear that our sled will leave us stranded on that long trip is the very reason we all pay attention to inspections … In your case its pretty amazing your sled got you almost all the way back.. A cracked chaincase should be rare and leaking oil, lack of oil, or high mileage may not be the end result that caused this chaincase to crack in my humble opinion….