Reply to "distributor gear lubrification?"

Clevelands don't have an inherent problem with distributor gear failure. The gear is normally a part of the motor taken for granted, it does what its designed to do just fine, it doesn't need to be re-engineered. There are countless 30 to 40 year old Cleveland powered vehicles on the road, with abused and tired motors, but never a problem with the distributor gear. If a 351C is having a problem with its distributor gear its because (1) it has been assembled wrong, (2) poor quality parts have been used, (3) incompatible parts have been used, (4) the wrong lubricants have been used, (5) the wrong parts for the application have been used, or (6) some aspect of the motor has been altered unsuccessfully.

The distributor drive gear needs the additive ZDDP, even if the motor is equipped with a roller cam you still need to use motor oil with ZDDP. The lack of ZDDP could lead to rapid wear of the distributor gear.

Distributor gears need to be manufactured of materials compatible with the camshaft core, in my mind that means either heat treated iron or heat treated steel. The oem gear is compatible with iron camshaft cores, but certain roller cams, like the Crane hydraulic roller cams, have steel cores and need to be mated with steel distributor gears (available from Crane). Some replacement iron distributor gears are poorly manufactured and wear very quickly, such as the gears you might purchase over the counter from an auto parts chain like Auto Zone, Kragen, etc. Bronze distributor gears are a race engine thing, they are designed for engines that are torn down frequently or only see limited mileage in a season of racing (trailered drag race cars). I wouldn't expect a bronze gear to last very long, but I know some guys who are using them on the street and getting away with it. I advise against it however.

Some cam manufacturers think high volume oil pumps can lead to rapid wear of the distributor gear, Ron makes a good point, very heavy motor oil could do the same thing. If the gear is installed on the distributor shaft improperly it could be binding against the engine block making the distributor difficult to turn. If the oil pump drive shaft (intermediate shaft) is too long it could also create binding and make the distributor difficult to turn.

-G