Timing gear failed, why?

[John Stone]

What are the symptons of a cam gear failing? I have heard stories of guys replacing them on the side of the road, but have wondered what were the signs of this happening, or how do you diagnose this when it actually happens?

In my case, the car quit running and the distributer bug wouldn't go around. Incidently, it was on the Kansas Turnpike with light rain and cold wind. Others I have seen were just loud knocking coming from the front of the engine. Carefully turning the timing pin around and pushing on the timing gear while idling will usually determine if the timing gear nut is loose.