I have a 67 fastback with a slightly modified 351C. I recently had the distributor replaced and have "snapped" off the bottom gearing of the distributor; not once but twice. Has anyone ever had a problem like this before ?? I am thinking that the guys whom replaced itare either using substandard or refurbished parts or they are not installing it correctly. Would appreciate any insight or ideas also, would appreciate any thoughts on quality mechanics in the Houston area. Thanks.

 

You mean, you sheared the retaining pin off?

 

I know some cams require a brass gear instead of the normal steel coated gear. Why I am not sure. I have also heard of some types of disti's breaking retaining pins, but I cannot remember which manufacturer had that problem. I have a Mallory Unilite on my Cleveland and the only problem it has had was a short in the electrical connection to the ignition box.

 

Most likely you are mismatching the cam and dizzy gear.
What cam is in the car?

 

If the gear is wearing out, yea probably a mismatch,, if it is breaking, it makes me think that maybe the oil pump is locking down from time to time,,,

(?? hole in pickup screen, a chunk of something getting sucked into the pump every now and then..... snap!! ??)

A broken distributor gear is an unusual occurrence, two broken gears points to something else causing this issue.

If the shaft is shearing off of the distributor, or if the roll pin is breaking (shearing), there is somthing "binding up" in the distributor itself, but for the life of me I can not imagine what would cause this.......

IMO, somthing other than the gear itself is causing the problem.