Date codes and other info for some, not all, BT trans cases

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Speeding Big Twin
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Re: Date codes and other info for some, not all, BT trans cases

#31

Post by Speeding Big Twin »

Below is another example to add to the list. Date code 5 61 indicating casting in May 1961.

May 1961.jpg
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Earlier in the thread I mentioned vent screw #34720-56 was placed in the trans lid as of 1956 models. This is confirmed by Shop Dope 372 dated February 6, 1956.

Shop Dope 372.jpg
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Another interesting document is Service Bulletin 439 issued March 29, 1961, addressing a change to the Duo-Glide speedo drive. Notice the last paragraph on page 1 says the letter C will be found stamped in a certain position on some transmission cases. I don’t recall noticing a C yet in that location so if anyone has an example then please let me know.
Eric

Service Bulletin 439 (page 1).jpg
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Service Bulletin 439 (page 2).jpg
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Service Bulletin 439 (page 3).jpg
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Speeding Big Twin
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Re: Date codes and other info for some, not all, BT trans cases

#32

Post by Speeding Big Twin »

In June 2016 I said I'd never seen a date code on a 34703 65 trans case and that was true. But here is one (1-77) indicating casting in Jan 77.
Eric

Trans case (1-77).jpg
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Trans case (underneath).jpg
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Trans case (front).jpg
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Re: Date codes and other info for some, not all, BT trans cases

#33

Post by RooDog »

Speeding Big Twin wrote: Fri Oct 18, 2019 10:53 am In June 2016 I said I'd never seen a date code on a 34703 65 trans case and that was true. But here is one (1-77) indicating casting in Jan 77.
Eric

Trans case (front).jpg
Eric,
What is the significance of the number you have redacted?
....RooDog....
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Re: Date codes and other info for some, not all, BT trans cases

#34

Post by RUBONE »

RooDog wrote: Fri Oct 18, 2019 1:59 pm
Speeding Big Twin wrote: Fri Oct 18, 2019 10:53 am In June 2016 I said I'd never seen a date code on a 34703 65 trans case and that was true. But here is one (1-77) indicating casting in Jan 77.
Eric

Trans case (front).jpg
Eric,
What is the significance of the number you have redacted?
....RooDog....
It is a unique ID number and is traceable back to the bike it came from by H-D often referred to as an anti theft number. It is the same format as the ones used on forks and frames.
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Re: Date codes and other info for some, not all, BT trans cases

#35

Post by Speeding Big Twin »

RooDog wrote: Fri Oct 18, 2019 1:59 pm
Speeding Big Twin wrote: Fri Oct 18, 2019 10:53 am In June 2016 I said I'd never seen a date code on a 34703 65 trans case and that was true. But here is one (1-77) indicating casting in Jan 77.
Eric

Trans case (front).jpg
Eric,
What is the significance of the number you have redacted?
....RooDog....

On the front of the trans is an additional original component identifying number, aka security code, aka anti-theft number, aka supplemental number. Some believe the practice began in 1963 while at least one publication said 1961. Several others say the additional ID began with 1962 models and I agree.

In the beginning, when used for Big Twins, it was stamped on the trans, frame and lower triple clamp and it consisted of one letter followed by either three or four numeric characters. Along with the SN and BNs, the additional ID on each bike was recorded at the factory and I imagine it may have been useful in warranty and/or recall situations. It was also of assistance to police when investigating bikes and/or parts thereof.

In the past, some forum members had all the additional ID on their bikes confirmed as original by H-D but as of more recent times it is unclear how much info the factory still has.
Eric
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Re: Date codes and other info for some, not all, BT trans cases

#36

Post by PabloDogboy »

Hi , this is my first post to the site as ive just joined, i have referred to your case number info a few times and thanks its been helpful. I picked up a case a couple of months ago thinking it was a 49 from the pictures i had, but when i got it in my hands i started thinking its a 39 as it has the bronze insert and the raised or rounded casting where the shifter is, can you confirm its 39 also date code is L 9 , i have pics but not sure how to attach yet. Thanks
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Re: Date codes and other info for some, not all, BT trans cases

#37

Post by panhead »

i have pics but not sure how to attach yet
How to add a picture/attachment to your post
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Re: Date codes and other info for some, not all, BT trans cases

#38

Post by PabloDogboy »

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Hi , thanks I think the photos are loaded
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Re: Date codes and other info for some, not all, BT trans cases

#39

Post by PabloDogboy »

Hi , more pics I had to resize them
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all
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Re: Date codes and other info for some, not all, BT trans cases

#40

Post by Speeding Big Twin »

PabloDogboy, again welcome to the forum. Thanks to panhead I can now see your photos. As you suspected the case was cast in 39 and in that year L indicated December so it may have been used as a 40 model.

Also notice the bosses for two mounting studs at lower left. Yours are the slimmer style and they too help identify the case as a late-39 casting as opposed to late-49.

Markings at the back of the case look like 40 and a horizontal 0. I’ve seen them several times before and my best guess is that they may have been stamped by an inspector as I mentioned above. According to someone else on the net a while ago the ‘40’ has something to do with a certain type of trans for 1940 models but he didn’t elaborate and I do not know if it’s true. Including yours, so far I’ve seen a 40 marking at the back of cases cast in April, May, June, August, September, November and December 1939. And March 1940.
Eric
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Re: Date codes and other info for some, not all, BT trans cases

#41

Post by RUBONE »

My guess would be the "40" differentiates it from a '39 which had the odd one year only shift pattern (1-2-N-3-4) in a 4 speed with '40 going back to the earlier configuration (1-N-2-3-4) making it easy to see on an assembled unit on the assembly line.
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Re: Date codes and other info for some, not all, BT trans cases

#42

Post by PabloDogboy »

Hi , and thanks for the replies and confirmation of the case year , sorry its taken awhile to catch up on the messages.

Yes not nice looking welding but i have seen worse while investigating the year of the case
Only grabbed it . because im sure its better to have a case than nothing at all , i will continue to search for a 47 case for my pproject.

Thanks to all
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Re: Date codes and other info for some, not all, BT trans cases

#43

Post by easykick »

Hello,
Here is photos of the 1965 transmission case, it has a repair, has been chrome plated and looks to have mounting ears and bottom bosses removed.
thumbnail_20220710_151938-1.jpg
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Re: Date codes and other info for some, not all, BT trans cases

#44

Post by Speeding Big Twin »

Casting number 34703 65 was used for 65 thru early-77. Unfortunately I can’t narrow things down on this occasion because I don’t see extra ID on the front. Normally a 34703 65 case has an additional original component identifying number, aka security code, aka anti-theft number, stamped on the front just below where the lid attaches. For example B1234. Apart from the letters I, O and Q which seem to have been skipped, the letter on the front of a 34703 65 case could be anything from B thru W and it indicates what model year(s) the case could have been used for. But I can’t see any additional ID on the front of your case so it may have fallen victim to the polishing and plating process.

Below the casting number is a lone character but I’m not sure what it is. Maybe E or 2? But unfortunately it doesn’t help us and sometimes in that area you’ll instead find a lone 1 while others have 1E.

On top of the case appears to be the letter D? But it too doesn’t help much with the model year of the case and I’ve seen it on these cases for 65–66, 69–70 and 72–74.
Eric
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Re: Date codes and other info for some, not all, BT trans cases

#45

Post by nifty »

easykick wrote: Sun Jul 10, 2022 10:09 pm Hello,
Here is photos of the 1965 transmission case, it has a repair, has been chrome plated and looks to have mounting ears and bottom bosses removed. thumbnail_20220710_151938-1.jpgthumbnail_ATT00001 (2).jpgthumbnail_ATT00001.jpg
Hi easykick & Eric and anyone interested.
To best of my knowledge,
No -65 casting number case has bottom bosses (alignment guides for tin primary trans)

EDIT It appears likely that in late 77, for 78model year, the single-thickness, pressed, tophat-section -65A mount plate appeared.

So IMO the easykick trans has only had its ally primary ears removed and likely also the ID number when polished for chrome.

Nifty
Last edited by nifty on Fri Oct 27, 2023 6:49 am, edited 1 time in total.
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