Thread size Trumpet Horn

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DuoGlide62
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Thread size Trumpet Horn

#1

Post by DuoGlide62 » Wed Jan 02, 2008 2:00 pm

After having my powerpak pop off the horn end a few times I need to come up eith a bulletproof fix. Does anybody know the thread size of the horn ? Knowing the thread size of the locknut (pt.# 69017-52A) would nail it down. Anybody else have this problem ? Thanks, Rick



FlatHeadSix
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#2

Post by FlatHeadSix » Thu Jan 03, 2008 3:21 am

Rick,

How are the threads on the trumpet tube and inside the power pack? The big nut is just a jamb nut and actually does more to push the power pack off of the tube than to lock it on there. The Dealer's Spare Parts Catalog does not show the thread size or pitch because it is not common hardware. The parts book does indicate that the original part number was replaced by a -52A which probably indicates that they had problems with the original part.

Sorry, I don't have a silver bullet fix for this one...

good luck!

mike
Image

Guest

#3

Post by Guest » Thu Jan 03, 2008 11:11 am

Horn assembly is a Delco affair, not Harley's own. Power packs and horns (the latter folded-up in a different shape) could be found on US cars as well. Nut size is 7/8" - 24 tpi.
JW

DuoGlide62
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#4

Post by DuoGlide62 » Thu Jan 03, 2008 1:09 pm

Thanks for the replies.
I just used the nut part number to try and get a thread size. The threads in the powerpak are suspect simply because they're tapped into the plate with no real thickness. The idea I have is to have a sleeve tapped to the size and after opening the hole to the o-d of the sleeve, weld or braze the sleeve in and machine to fit. I know it sounds like a big job but my buddy's got a machine shop.
I'll get pix when I do it and I'll show everyone my solution to to the 6 V horn on a 12 V conversion. ...Rick

(mike, Maggie Valley next July ?)

FlatHeadSix
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#5

Post by FlatHeadSix » Thu Jan 03, 2008 5:54 pm

It sounds like a good plan Rick. A threaded bushing thicker than the original plate on the power pack should give it a few more threads to grab on to and hold the 2 pieces together, as long as you can anchor the bushing securely to the power pack. Kind of like a big Heli-Coil. Let us know how it turns out.

JW is correct, Delco made the pack and Harley made the trumpet. I never thought about it but I'll bet he's right about the automotive applications, the same pack with different trumpets was probably used on a whole bunch of different cars. I had a Studebaker that had a pair of them mounted vertically between the radiator and the grill. I imagine that the automotive units are getting just as scarce as OEM Harley.

I have Maggie Valley on the calendar, I saw your other post a few days ago and forgot to reply. I'll know more as we get closer to the date what my work schedule will allow, I'll keep you posted.

mike

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#6

Post by john HD » Fri Jan 04, 2008 12:01 am

rick

i have an old junk power pack you could use for donor parts.

i would think you could drill the rivets and use the plate.

john

DuoGlide62
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#7

Post by DuoGlide62 » Sun Jan 06, 2008 3:04 am

Well, this is a case of thinkin' too much before gettin' my hands on the parts. I 'thought' the problem was the threads in the powerpak. Today I got the horn off and discovered that it's actually the threads on the trumpet that are worn. I guess I'll have to keep my eyes open at the swaps for a better one.
I'll post some pix soon of my 12 V fix of the powerpak soon.
Thanks for the responces. ..Rick

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#8

Post by Cotten » Sun Jan 06, 2008 3:37 am

Well Geez, Rick,...
You can't just toss that Jubilee away!

(Although I might...)

If you can get Milo to lathe-cut a drift that is just a couple of thou fatter than it's inside diameter, it might be possible to drive it in (with gentle heat?) to swage the threads outward. At least for a last hurrah.

Obviously I do not have much respect for Jubilee horns.


....Cotten

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#9

Post by Panacea » Sun Jan 06, 2008 5:06 am

My pan came with one installed. I thought it looked OK but sure makes it tough to adjust pushrods. I'm kind of a "less is more" type. I'd sure do a trade for some speedster bars. Mike

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