J model frame numbers

[MMasa]

Letter code

Herb
The letter coding seems to have started in 1912 and it does start with A
A = 1912
B = 1913
C = 1914
D = 1915
E = 1916 and so on.

It wasn't just used on three speed transmissions but seems to be somewhat ubiquitous. Look at the factory numbers in a pre 1925 parts book. First letter is this date code and second letter is a group code (motor, fastener, electric. etc). I haven't decided yet as to exactly how the letter code was applied. Whether it was a code for the year the part number was created, or the first year it was used on ANY bike including pre-production units or does it only apply only to the first production year bike it was used on??? In most cases it seems to apply to the year that a part is generally accepted as being used in production but there are a few exceptions. This letter code also applies to many (all???) forging numbers. Look at the forging numbers on connecting rods and correlate it to the first year that rod was used. 61" JD rods are DA (D=1915 A=motor group) 74" JD rods are JA (J=1921 A=motor group) Knucklehead rods are XA??? (X=1935?? A=motor group). Were they going to try to introduce the 61 OHV in 1935? As always.... VERY puzzling.
Mark Masa

[Robert Luland]

This thread might be old but its great in its content. My question has to do with production. On Panheads for instants, unless your bike had a late vin the tranny was made and dated the year before. Would the same rule apply to my 22JD. J or K tranny date?
Thanks, Bob L

[exeric]

I didn't know you had a JD Bob. Got any pictures?

[Robert Luland]

No pics to be had Eric. I have pieces. This is going to be a long haul! Info, Info , Info! Learn, Learn, Learn quick! Nice to hear from ya Eric. I hope all is well. Bob L

[MMasa]

Bob
You're correct that the foundry date codes often show the previous year number. My early 1948 panhead engine cases have 1947 foundry date plates. I don't however think this is the case with the hand stamped numbers on jd frames, engine cases, and trans cases.
Mark Masa

[MMasa]

Bob
Btw, what year and model is your jd? What are you missing?
Mark Masa

[Robert Luland]

Thanks Mark, I'll have that info Saturday night. bob

[rwm]

bob just bring the stuff to jefferson and sell it to me. you panhead guys don't need to mess with a 22 jd. i'll even give you back all your boxes and storage bins after the parts are in my car.

[Robert Luland]

That's mighty white of ya Rob since because of what happened at Oley, we have all new storage bins.

[Robert Luland]

Mark, I got the goods today. Its a 22JD73XX. So I still have to figure out the story with the date coding. It seems to me that since the number is stamped not casted, that it was done on the production line during assembly? Anyone want to chime in on this. Is your tranny year the same as the vin. I have my choice of either K or J. It would be nice to get it straight the first time around. Is there anybody out there that produces aftermarket tools for this motor. I need the specialty spanner wrenches. with all that said and done, who's got a 22 frame they want to sell Bob.

[exeric]

From what I've seen Bob, you have enough stuff in your shop to make this case nut wrench. I made this years ago and even though it's not heat treated, it still works well.

[dlm32]

Robert,

Competition Distributing in Sturgis, SD. sells the case screw sockets (get 2, it makes loosening/tightning easier), intake nut wrenches, etc. Doesn't really take lots of tools to pull down a J/JD. Removing the pinion gear is usually the biggest pain.

[23JDCA 808]

Mark, I got the goods today. Its a 22JD73XX. . . . I have my choice of either K or J. It would be nice to get it straight the first time around. . . .

(This following info from Mark Masa of www.linkcycles.com)

Almost all 1915 - 1927 transmission cases are marked with a date
code. It's located above the transmission filler plug on 1915 - 1925
models and in the same location on 1926-27 models, however since the
oil filler is now moved to the front right side of the case it's no
longer "above" the filler. It's a letter (D-M on 1915-1924)or a two
digit year (25-27 on 1925-1927) followed by a sequential serial
number (starting at 1000 I think). I have never seen a case stamped
with 28 or 29 but I have seen 1926 later styles with no number. I
assume that these are 1928 and or 1929 cases. The 1925-1927 system
is self explanatory however the letter code goes like this.

D = 1915
E = 1916
F = 1917
G = 1918
H = 1919; “It's a later 1919 trans case. The H denotes 1919 and the A (suffix) indicates that it was set up with the new clutch introduced in mid 1919. This clutch was used mid 1919 thru 1929 with only a slight change in 1929. It would have been fitted with the new style mainshaft and the kicker cover you have shown. The "A" is in 1919 motor numbers that were fitted with the new clutch too. It is a common misconception that the "A" stands for Army. This is incorrect. I have HD factory literature explaining the meaning of the A. Mark Masa”

I = 1920
J = 1921
K = 1922
L = 1923
M = 1924

[MMasa]

Bob
You want the trans case with the K on it. The number on the trans case should be somewhat close to the vin but it would be highly unlikely that they match exactly. Most original bikes that ive seen have numbers within hundreds to maybe a thousand apart. Your vin is under 8000 so you should have the alloy gear case cover / oil pump and NOT the stamped steel cover with the cast iron oil pump. Sorry, but I don't have an extra frame at this time. Send or post some pics of what you have and we'll see what we can do to help nail down exactly what you have.
Mark Masa

[Robert Luland]

Here ya go Mark