Thread size on the distributor shaft to tighten the cam screw?

[Ken Ehrenhofer]

HELP, Any body know the thread size of the distributor upper shaft where you tighten the cam screw into??? the thread on the cam screw???
Thanks,
Ken

[John Stone]

5/16 X 24 ought to do it.

[Ken Ehrenhofer]

No John, That is what I tried and it screwed up the threads inside the shaft. I tried my thread gauge on it and i cannot find a size to fit????
Really wierd,
Ken

[Jim Parker Toronto]

Is it Metric?

[Keith True]

I have a very old thread guage that belonged to my great grandfather,he had a machine shop but was an engineman/machinest in WW1.Years ago I was playing with a shaft with screwed up threads and found nothing to fit it.I checked it with his old guage and did come up with the proper one,but it was such an oddball I could not find a tap.I forget what it is,but the guage is in the toolbox draw and there is an old dist.shaft in with it.The shoulder on the shaft is turned to drive out the old bushings.It is a tool that happens to sleep with the thread guage.I will try to remember to check it when I go to the garage tomorrow.

[Ken Ehrenhofer]

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Originally Posted by Jim Parker Toronto

Is it Metric?

I am leaning that way also. I measured it to be 8 MM O.D. but i do not have a metric thread gauge so it will wait til tomorrow.
Thanks to all for trying to help,
Ken

[Ken Ehrenhofer]

Originally Posted by Keith True

I have a very old thread guage that belonged to my great grandfather,he had a machine shop but was an engineman/machinest in WW1.Years ago I was playing with a shaft with screwed up threads and found nothing to fit it.I checked it with his old guage and did come up with the proper one,but it was such an oddball I could not find a tap.I forget what it is,but the guage is in the toolbox draw and there is an old dist.shaft in with it.The shoulder on the shaft is turned to drive out the old bushings.It is a tool that happens to sleep with the thread guage.I will try to remember to check it when I go to the garage tomorrow.

If you could wake up that old tool tomorrow I would be thankful,
Ken

[Ron in Quincy]

Why don't you just call Walt Bratton, they sell the new shafts, cams and cam nut ?

Walt is always very helpful to us Aers !!!!

Ron

P.S. I do not know the thread size !!!

[dave in australia]

It's an oddball thread alright. It's 5/16 x 30 tpi. When I first measured it, I thought it was 5/16 ME, which is 32 tpi, but when I tried my tap by hand, it screwed in about 3 turns and stopped. Got out the thread guage, yep, 30 tpi, I tried 26, 28, and 32, but 30 is what it is.

[Craig Lewis]

Dave, you boys were hit with some SEVERE flooding down under
That's gotta mess-up one's life...are you OK?

[dave in australia]

Originally Posted by Craig Lewis

Dave, you boys were hit with some SEVERE flooding down under
That's gotta mess-up one's life...are you OK?

Thanks for your concern Craig. The floods are in central Queensland, which is approx 1500-1800 miles north of where I live. The area affected is the size of France and Germany combined, about 400,000 square miles. Queensland is Australia's second largest state, about 715,000 square miles or about 1/4 of Australia. The area in Australia where I live is more affected by bushfires than anything else, which thankfully none have been started yet.

[Tom Wesenberg]

Originally Posted by Ken Ehrenhofer

HELP, Any body know the thread size of the distributor upper shaft where you tighten the cam screw into??? the thread on the cam screw???
Thanks,
Ken

The Parts Price List has this A-20744 listed as .325 - 30.

Ken, I'll bet you have the "Parts Price List", but for those who don't, it's a very good book to own. I think every parts house sells a copy of the 1931 edition.

[John Stone]

Originally Posted by Ken Ehrenhofer

No John, That is what I tried and it screwed up the threads inside the shaft. I tried my thread gauge on it and i cannot find a size to fit????
Really wierd,
Ken

Yep, I was wrong. Serves me right for going out in the cold garage and just guessing. My 1929 Parts Price List says .325-30. You are right, weird.

[Terry, NJ]

Originally Posted by Tom Wesenberg

The Parts Price List has this A-20744 listed as .325 - 30.

Ken, I'll bet you have the "Parts Price List", but for those who don't, it's a very good book to own. I think every parts house sells a copy of the 1931 edition.

That sounds suspiciously like 8 mm X 1.25 25 mms per inch = .040 x 8= .320 (plus .005 for the oversize ground on all taps) = .325 X 1.25.
Who knows what mysteries lurked in the mind of Henry Ford? Anybody who would use #12 X 24s has to be a little nuts.
Terry

[rob mcdonald]

I guess the fine thread, .325-30 is to insure a tight lock of the cam.

Distributor Cam Screw And Washer
Code:A12211/13
Price: $1.25
Model Year: 1928 - 1931
UOM: Set
Quantity in Basket: none
"This Special screw with washer holds the cam to the shaft. Now has an oil hole, especially made for A12178M, but no problem being used on original upper shaft."

[dave in australia]

Originally Posted by Terry, NJ

That sounds suspiciously like 8 mm X 1.25 25 mms per inch = .040 x 8= .320 (plus .005 for the oversize ground on all taps) = .325 X 1.25.
Who knows what mysteries lurked in the mind of Henry Ford? Anybody who would use #12 X 24s has to be a little nuts.
Terry

It's not 8x1.25, I have one of those taps and it didn't even go in half a turn. Plus I think you've gone the wrong way with your thread calculation. Thirty tpi or .0333" per thread pitch is .83mm, ie .0333" divide by .040"(1mm). So it's not metric.

[Terry, NJ]

Originally Posted by dave in australia

It's not 8x1.25, I have one of those taps and it didn't even go in half a turn. Plus I think you've gone the wrong way with your thread calculation. Thirty tpi or .0333" per thread pitch is .83mm, ie .0333" divide by .040"(1mm). So it's not metric.

Hmmm. Metric threads are a mystery to me. Lessee, 1 mm = .040, 1' = 25mm. or 25 threads per in. (1.00mm pitch) 30 TPI=..., ahh crap! It either fits or it don't and it don't! It sounded good for a while while! Whereinhell did Henry dig that one up. It isn't even a 1/32 size, 11/32 =.343. Reminds me of a lathe headstock I have 1 1/16 X 16 spindle nose thread. Cheers! Terry