@Road Trip
Other than going through what drifter went through, is there a way to know that the gear was installed correctly by the manufacturer?
It’s been a while now, but I think mine had a dimple and an engraved mark that when aligned put the rotor between the cam sensor and the #8 triangle. Not sure if all distributors include those markings or not.
(insert view of me climbing out of the rabbit hole, eyes glazed over from reading endless dizzy discussions. :0)
Greetings east302,
I have 2 answers to your question. The first was when the world was right.
And the second, slightly more involved answer, is what we have in 2024.
In the Beginning - How to verify when the 13 tooth gear on your Vortec distributor is properly phased:
Once upon a time, there was order in the universe.
Distributor gears had dimples. Period.
IF the dimple was on the same side of the distributor shaft as the installed
rotor's 'spark terminal', your 13-tooth gear was properly phased. P1345 codes were avoided/cleared.
Note: Reading around, a GM dizzy specialist wrote the following, which appeals to my sense of balance:
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(credit: https://www.davessmallbodyheis.com/services/general-motors-distributor-gear-information)
Now if you remember the big ol' HEI rotor, at 3000 rpm (distributor, 6K crank)
I bet that 'firing bar' could create a vibration that a dimple could counterbalance?
If nothing else, this gives me a perfect mnemonic to help me remember that the dimple is paired with the rotor's firing tip.
2024 - How to verify when the non-dimpled 13 tooth gear on your aftermarket dizzy is properly phased:
And when the aftermarket guys muddied up the waters by skipping the dimple, we now have to focus on the roll pin
and it's orientation to the gear teeth above. Check this out:
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(credit: rotor + hardware photo eBay auction? All the value-added techo-grafitti = yours truly. :0)
Q: How confident am I about this advice?
A: Very. Back in March of '02, there was a guy named Schurkey on the Chevelle forum:
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How cool is that? For every right answer out there, there were at least a dozen wrong answers
covering it up. And this was a confusing subject even before folks started replacing worn out
Vortec distributors with affordable aftermarket jobs (that were mis-clocked at the factory), only
to end up with extra tough to clear P1345 DTCs.
Of course I was trying to find really sharp pics of the roll pin under the valley between 2 teeth,
but all the photos I could find were of low quality? But if you have a dizzy in hand, just compare
it to what Schurkey wrote almost 22 years ago & you should be able to tell at a glance.
That's all I've got to say about that.
Cheers --
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