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Greetings stovebolters, I need to change my cast iron distributor gear (1958-1960 235 distributor) for a steel gear off of my 1947 216 distributor. As you guys know, they don't have a pin holding them on. They have a dab of metal on each side, which I ground down, but found no pin to punch out. Are these pressed on, or what is the usual removal process? Thanks

first is the steel one ground down, second is cast iron.

Take a closer look. If your like most of us, put on your 3x cheaters. That dab of metal that you ground off is the end of the pin that was factory swaged. I can see in your picture a slightly different color where the pin is. Use a slightly smaller pin punch (with a flat face) and back the gear up on a vice opened about 3/8”. You may need a helper to support the distributor so you can use two hands for the hammer and punch. Lightly tap that area with a small hammer and that punch and the pin should reveal itself.

Good Luck!

I did see that nice little round metal spot, but was not sure if it was a pin. And how do I go about securing it to the other shaft? Maybe tach weld? Thanks for the info Phil

I used a similar sized roll pin, tapped it thru, cut it off with a cutoff wheel, then ground it flush to the gear.

Make sure you don’t leave any burrs and clean up any metal filings that might get into the crankcase.

Thanks Phil, I used the same pin, I was able it had just enough metal left that I could mushroom it just a bit. I doubt it will work its way loose.

That’s good to here. Congratulations on your sucess!

This is from Deve's TechNet (for next time - if there is a next time)

To reinstall the gear, get the proper length and size of roll pin. I use high strength stainless steel ones from McMaster-Carr. The 3/16" pin will be tight in the shaft, but I do not rely on that single roll pin. Put another M2.5 (x30) pin inside the first one making sure the openings are opposite each other. This almost guarantees that gear isn't going anywhere. Test it to make sure there is no slop introduced by the pin combination and then cut off the pins flush same as the one that was there in the first place. If by some chance there is any slop in the gear to shaft connection, drill both the gear and the shaft out to the next size roll pin combination which is 7/32" and 1/8".

The delco remy number for the pin references a roll pin that is the same length as the sold pin that comes with an nos gear. The solid pin was to be squashed peened down but the roll pin is not so the roll pin Is actually too long so you have to cut them down after install. A roll pin for a Ford is actually a perfect fit.

On the other hand, and believe it or not, you can safety wire the pin on our distributors.

This is timely for me, I am in the middle of an engine (235) assembly now. Have a nos gear I'm using.
I wonder though how a non rated 2.5mm spring pin that is only 1/2mm thick inside the 3/16" pin is really going to make a difference in the overall picture. Any others want to offer up an opinion?

Never seen a failure with one spring pin.
It's the way most manufacturers do and have done it.

If you think about it, the most likely reason for the pin to shear is a total failure of the oil pump. In that case I personally would prefer the pin to shear than destroy the tang driving the oil pump or distributor.

Good point!

I have seen spring pin failures on a distributor drive, but not on a Chevy engine. The same Ford 300 engine sheared a spring pin twice within a couple of months. After the second failure, I pulled the oil pan and found that the sump had a lot of debris in it from a failing timing gear. The teeth had a plastic coating on them that was breaking down into granules about the size of a match head. The oil pump pickup screen also had holes in the mesh strainer big enough for those pieces to get sucked into the oil pump.
Jerry

I have never had a roll pin failure with a single pin. I safety wire my personal distributor rebuilds primarily because Jim Linder (gmc bubba) did that to one of mine before he stopped doing them so belts and suspenders for me.

On the other hand, my vertex magneto for 235/261 uses a single roll pin. I purchased the vertex as a rebuilt unit from vertex back in the early 80s and have run it up to 6000 rpm no issues with the pin. So I do think a single pin is no problem, that and I am with the others, rather a pin shear then have the tang get taken out on the vertex.

For what it's worth, perhaps not much, but I once had a 57 Pontiac with factory Rochester Fuel injection. The injection pump was driven off the distributor. The distributor gear was pinned to the shaft with a roll pin -- which sheared more than once. I went back to the dual four barrel setup.