case vac keep breaking dist. drive gear pin

[big dynasty]

I have replaced the drive gear pin 3 times it will run for a while then it breaks
what might cause this problem

 

[boomer1025]

Sounds like you have a lot of end play in the camshaft or a lot of play in the dist. shaft

 

[638]

Might try pulling the Distributor shaft out of the Disttributor and clean and oil the bushings and shaft.