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What is the diameter/thread count for the armature shaft end that is threaded for the pully nut? The armature is the one used in all '29 through '39 generators. I'm guessing it is a 11/16 x 24 ? I've messed up the threads on an armature, but hope to be able to repair it. TIA, Bob


The 1929 Chevrolet: The Most Outstanding Chevrolet In Chevrolet History

Well I've answered my own question! The diameter/thread count is: .669/20. Found it on eBay of all places. Now to try and find a die that size. What does .669 come out to in fractions? Bob

The 1929 Chevrolet: A Six In The Price Range Of A Four

Did you mic the shaft?
11/16" = 0.6875" .6693 is equal to 17 MM that seems to me to be way too large, are you sure it isn't a 7/16 20 thread, the same as the lug nuts? have you tried a lug nut on the shaft?

the closest inch is 85/128" is equal to 0.66406
171/256" = 0.66796"
43/64" is equal to 0.671875"

There is a special adjustable thread chasing tool that is used to repair the threads on various sizes of armature shafts.

Or you can use a thread file to straighten the threads. They come with four thread pitches on each end. Takes a little practice and time but do a good job of fixing OOpses.

MrMack: I didn't even think about using a mic....duh! The armature shaft diameter is definitely larger then the lug nut
bolt.

JYD: I just might look around for an older automotive electrical repair shop. That would be where I would find one
of those tools you mentioned I guess.

Chipper: Good idea! I'll have to remove a little of the "mushroom" (don't ask how it got there) from the end
of the shaft first.

Thank ya' much guys the suggestions are much appreciated.

Bob

one word, Brass

Dads 31,
I tried brass at first then went to steel. A lack of patience is a very nasty habit. You'd think I would have learned by now! Bob