I hear rumblings that the one-way bearing was problematic, and was eliminated or replaced? this is in 2012 or so..I don't know myself, but I have the same trans presumably updated. Nice blowup though, haven't seen that around till now, thanks!
Here's something else to think about; I also hear(late it seems) that this trans is hard to find parts for/order from china, and the best option is the american made trans, ezm. I would jump on this myself, but I hate to jettison the 4G till something happens..which might be soon, because the clutch takes a beating on takeoff, even when I stand to pedal. I'm thinking of drilling out some clutch material to lighten it up and engage later..also there are threads describing how to mod it for reliability.