I think these pictures would interest you. Tractor was in third gear making a right hand turn. When the shaft broke the ridge-buster must have dug into the dirt and pivoted the tractor over. The driver jumped/flew off uninjured, just "shook up". I got another shaft and had it running the next day with the help of a good mechanic and his lift truck.

Man, that's one way to ruin your whole day .. .. the operator was obviously travelling at speed, for the tractor to flip?

The pivot shaft appears to have been cracked across more than half its diameter, for a long period of time. Regular careful inspections of a tractor, looking for leaks, cracks, loose fasteners, items out of alignment, or unusual wear patterns, will often pick up things like this. However, the area where the crack is, is not the easiest place to see or find cracks.

This kind of failure is rare, but not unknown. While you are in charge of powered equipment, there's always the possibility of some mechanical failure event that can come out of left field, and catch you unawares. I think any of us that have operated equipment for lengthy periods of time, have had them.
Rapid response to emergency situations calls for quick reflexes, a cool head, training, and maturity. Another good reason for ensuring you don't let your 6 or 7 yr old operate a tractor unsupervised. I trust the operator was O.K.

It appears as though when the pivot shaft broke the left track frame became one with the sprocket and rotated up onto the idler and tipped the Cat. I can't quite picture how this would happen, I would think slack would develop in the track and it would jam up under the fender and stop the Cat. It looks like the Cat was just discing on level land. Was a left turn being made? It would make sense the shaft would snap while(st) turning.

Tom

Wow!!! That's nasty:eek:
I can see the For Sale sign now "Running when parked" LOL