The Distributor gear is missing about 3 1/2 teeth. The Cam gear that it mates to seems no worse for the wear from what I can tell. Should i just replace the gear? or is there some underlying problem that needs to get fixed?
I have a '78 F-250 with a 400.

 

What led up to this problem ? Did you change the dist for some reason ?

 

I cant remember off hand which is right, but make sure the cam gear is made out of the correct metal. I dont know if it is supposed to be brass, steel or something else. If it is supposed to be brass and you have a steal one, the stress can snap teeth of of the harder less flexible metal. Could also be that your oil pump is messed up. That gear runs the Distributor and the Oil pump. We need more details of the history to go any further.

 

Do you have a high volume oil pump or a roller cam?

 

First hand experience of this problem for me was that I had installed a high volume oil pump and the load it puts on the cam gear to distributor gear is too much and it will eventually wear out the distributor gear. Although the cam gear doesn't look warn out it probably is and will continue to eat up distributors. Many fords don't have adequate oiling to support the increased load from an hv oil pump. There are some tricks you can do like drilling a hole to spray more oil at the gears but I don't know exactly how to do that. My fix was a new cam and a standard stock oil pump. Then again as stated in other posts you need to have the correct material for the cam you are running. At stock cam needs a cast gear and a roller cam needs a silicon-bronze gear (unless your roller cam has a pressed on cast gear then you can run the stock gear)

 

Everything is stock in the motor, no replaced dis. I was just starting out on a camping trip with a camper on the back and about 400kms into the trip the engine just died, I am going to have a look at the oil pump because everything else looks fine.