misaligned oil pump and/or wobbling distributor shaft

Has anyone seen the following part failures? I haven't begun the teardown yet, still looking for possible causes of a nasty distributor knock.

-an oil pump installed crooked on the block, so its split shaft doesnt line up to the distributor shaft?

-a distributor shaft and bushing so worn the rotor physically hits the contacts inside the dizzy cap?

-a wobbly distributor drive gear with excessive wear on one side?

-a well-chewed camshaft distributor gear on an OEM camshaft?

My distributor is tightened down, timing is correct, and a worsening knock is coming from up the dizzy shaft and radiating down into the oil pan. Its starting to affect the idle, like most problems it smooths out with higher RPM. There is no miss.

I've already ordered a new repro distributor pn #53006150. Ouch.

the pickup may be hitting the side of the oil pan. I have heard of that problem quite often.

I suppose this is why race engine builders weld the pick tube on the pump.

The knock was loose torque converter to flexplate bolts.

Like any poor fool, I had lots of ideas, and they were all wrong. The knocking sound was loose torque converter to flexplate bolts.

It was still knocking hard in drive, that fact threw me off the trail. I thought the knock would stop under load if it was loose converter bolts.

The knock came strongest from the oil pan sump, and thumped strongly through the distributor cap.
Even with a funnel tube stethoscope directly on the inspection cover I didnt hear the knock, it travelled silently through the block and came out through the lightest weight parts like the oil pan and distributor!

Now I know. Accurate "ear diagnosis" comes from experience only. And there's no substitute for having "been there, done that".


My mechanic knew that sound right away. Cancelled the dizzy order too.