Anyone have any ideas why this would break like this? The dogs that broke off this 3rd pinion gear hold the 5th pinion gear destroying the gear and shift fork. The dogs dont seem to be rounded off at all and ive never had an issue with the bike shifting or holding a gear while riding. If it makes a difference or not, I do ride alot in 5th gear. My bike is an 08 yz450 and the damage happened while riding in 5th. Ive already ordered the parts but I'm scratching my head on why this happened.