73-87 Chevy _ GMC Trucks > Fuel Systems and Drivability

Found a Quadrajet

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Mr. Machanic:
Got it all pulled apart.
Oh, that was fun! Seriously.

In the throttle plate, the primary shaft is worn and it shows on the shaft. It's .005 or .006 undersized. The unworn diameter is .308 and the worn spot is .303 and it is easy to see the movement in the throttle body plate.
I can seem to find primary shafts. Secondarys are easy to find. Just not the primary.
Any websites that may have a good one?
Thanks.

JohnnyPopper:
Looks like you pulled it from the bottom of a pool...hope she cleans up, will be watching this thread. I've done my share of QJ rebuilds with mixed results.

Mr. Machanic:
What is this "thingy"?

Mr. Machanic:
So....
I was not aware of this broken boss when I purchased the doner.
It was night time and out in the middle of sellers drive. (No excuses, just info)
The tube is slightly bent, but I can straighten that, or make a new one. No big deal.
The boss repair will be an interesting challenge.
But first, a bath. As my kids used to say, "It's poofy." They couldn't say, "filthy".

Mr. Machanic:
The plan is to sleeve the boss.
First, the tiny raised ridges on each surface is taped off so they are easy to see.
Next the body is lightly clamped up to angle plates as the little plane is indicated flat.
Then the boss is indicated in to align the spindle to its center.
Once all of that is done, the fractured pieces are removed and then the boss is given a clean deck.
You might notice the 3/16" tube hole is not concentric to the boss, so the center of the hole is picked up and that becomes the new center.
Now the boss can be externally bored to generate a true and straight boss to receive the sleeve.
The endmill is switched out for the boring head and a minimal amount is removed to accomplish the desired geometry.
Measurements are taken and a sleeve is machined to match.
A light press fit is made and then the 3/16" hole is reamed thru to the original hole.
The sleeve was made a few thousands long and now it too is decked off to match the adjacent boss which supports the vacuum plate.
Burrs and chips are removed and it's done.

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