J model frame numbers

[exeric]

Speaking of Harley Davidson numbers. Can someone shed some light on the frame numbers that appear on J model Harleys. I refer to the numbers on the top frame bar just behind the front seat mount lug. Is there any correlation to the year of birth ? Are there always the same quantity of numbers, (i.e. 4, 5, or 6 number string) ? For how many years did H-D number their frames in this location ?

[Tommo]

Eric,
Some time back this issue was discussed at some length but I can't remember exactly what the topic heading was so am not able to direct you to it.
I've got frames as early as 1918 and as late as 1929 that are all dated and numbered.
The following are examples of this:
29 H 1336
27 F 7288
26 F 5288
25 F 6145
25 F 5487

The 1929 frame probably came from a two cam bike as it had I beam front forks in it when I got it and it is the only frame I have ready access to that has a different letter code.
All the other cast shoe type frames have a F letter which normally equates to a mag model bike
I've got two loop frames away being repaired at present and the frame numbers on them didn't show up until the steel strips soldered to the top of them were removed. Both these frames are date coded 18 F and 20 J respectively.
The only frames that don't appear to be stamped are those supplied by a dealer and used to replace a damaged one.
Hope this helps.

[23JDCA 808]

http://www.antiquemotorcycle.org/bbo...ad.php?t=12550

I think the conclusion was that if a frame number exists, it is from a sub-contractor and not related in any manner to the engine's vin. We were talking about the Harley J and JD's, 1916 thru 1929. ...bill

[Chris Haynes]

My 1927 JD has engine number, 27JD 13741. On the top frame tube in front of the seat pogo casting is 27 F 9845. On a boss on the rear of the transmission is 27 9942.
George Hood, who does a lot of JD rebuilding, says he has never seen a bike where any of those numbers match.

[exeric]

The reason I asked about the frame number by the seat is, my 1916 frame is missing the tank mounting strips that carry that number. Also, the frame was very rusty and even if the strips were there a number would have been lost. I would like to stamp a number in the frame that generally represents that year since I'm in the process of restoring the frame. From the numbers that Chris and Tommo provided, it looks like the frame tube numbers ascend with the year. I was surprised to read that there are numbers under the soldered tank mounting strips Tommo. Again, my frame was too rusty to see anything like a number in that area. Thanks for the information.

[HarleyCreation]

Opps!

Just finished writing an article/column about Harley serial numbers. Seems that 1927 was the last year that Harley talked about production frame numbers in that period.

That "29H" marked frame is another anomaly of which there is so many....

[marsh1915hd]

HI Bill , I have owned a 1917 J that had 17 numbers on the rear tank strip. ON top of it. I do have pictures of it. I have seen a few over the years with number on the strip. These were 1919, 1920, 1922. Most of the time the tank strip is missing. Terry Marsh

[HarleyCreation]

Frame Numbers

Speaking of Harley Davidson numbers. Can someone shed some light on the frame numbers that appear on J model Harleys. I refer to the numbers on the top frame bar just behind the front seat mount lug. Is there any correlation to the year of birth ? Are there always the same quantity of numbers, (i.e. 4, 5, or 6 number string) ? For how many years did H-D number their frames in this location ?

Back to the original question which just came under scrutiny the past few days.

Harley began numbering frames in 1916 and continued that practice until 1927. At least 1927 was the last year they mentioned it. The year stamped was the year of frame production. I'm not sure what you mean by "same quantity of numbers," but frame numbers were culmulative and typically included several different models together.

Frame numbers are useful altho not definitive. For example, I have a "JD" frame here that I long assumed was a 1928 or '29 model because of some 1928-'29 JDH parts that came with it. However, I just looked and it is a "26F16xxxx" numbered frame! Very likely it is NOT from a 1928 or '29 model after all.

Very interesting subject with much still to learn.

[Chris Haynes]

What about transmissions? I just saw on with 28 numbers on it.

[exeric]

1916 rear axel carrier forgings do not have the ubiquitous H-D raised numbers. For that matter, I haven't seen numbers on any of the frame forgings of the '16 frame. My 1920 frame had forging numbers on many of the frame lugs and of coarse, later Harleys are rotten with forging numbers. I have wondered if this was because (by 1916) their product line was increasing and they had 12 years of diverse inventory that was confusing everything. . . . .Opinions?

[HarleyCreation]

What about transmissions? I just saw on with 28 numbers on it.

I haven't looked into trans numbers but I know they used them in the 1920s and possibly earlier. Trans numbers at times had some letter codes in them I believe. For some reaso the documents I've been looking at do not mention trans numbers at all. They seem to have had less priority than motor and frame numbers.

[HarleyCreation]

1916 rear axel carrier forgings do not have the ubiquitous H-D raised numbers. For that matter, I haven't seen numbers on any of the frame forgings of the '16 frame. My 1920 frame had forging numbers on many of the frame lugs and of coarse, later Harleys are rotten with forging numbers. I have wondered if this was because (by 1916) their product line was increasing and they had 12 years of diverse inventory that was confusing everything. . . . .Opinions?

No clue at all about forging numbers. Once the parts were used forging numbers don't seem to enter the picture at all. Not that I can see anyway. The numbers spoken of most frequently were: motor numbers, frame numbers, belly crankcase numbers, trans numbers, and ignition unit numbers. Depending of course if they were still stamping them with those number systems as over time some of them were discontinued.

[23JDCA 808]

. . . Trans numbers at times had some letter codes in them I believe. For some reaso the documents I've been looking at do not mention trans numbers at all. They seem to have had less priority than motor and frame numbers.

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

[HarleyCreation]

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

Very good info!

You gotta wonder why they started with the letter "D" and not "A".

1915 was the first year of the 3-speed gearbox so wouldn't that logically be year/model "A"?

Was there a reason for "D" or was it just one of their crazy too-much-Milwaukee-lager whims?

At least what at times appears to be whimsical or is there a logical method at work here?

[Steve Slocombe]

Like Mark I haven't seen transmission case numbers after 1927. The 1928/9 JD gearbox is seen relatively frequently on VL basket cases, as it is presumably a cheaper substitute for the VL box. The adjuster bolt does not line up but the box can still be held in by the bottom studs and nuts.