I was tightening my chain today after putting my 3 inch track on, and its been a long week...but anyway i read my manual and saw 21 foot pounds read it 3 times cause i thought 21 foot pounds was way to much..anyway i said well thats what the book says. well anyway i was snugging it up and i heard a pretty loud pop. I took the cover off and could find anything wrong then i realize i really screwed up. But my guess is the chain was in a bind and not on the sprocket right, since it hasnt turned over much since i put the track on. I cant find anything broken yet...but was looking for more places i might have missed to look or something. I haven't taken the chain off to see if something broke in it though i didn't think that could be it.