Significance of an "X" suffix in an M-series truck's serial number?

[migral23]

Hello readers.
I've been away awhile due to laptop/computer issues.
As the title line says, I'm wondering if an "X" suffix in an M-series truck's serial number has any special significance. This is regarding a 1948 M16.
Previous M-series I've owned have had only a 5-digit serial number, with no alpha suffixes. Nothing I can find in my original copy of a Parts Catalog for M Series Trucks (my only reference book) covers this question. Thanks to all commenters.

Mike Auldridge, Gaithersburg MD

[dclerici1]

Just throwing this out there, but 2 words come to mind. Truck was produced for "export" or maybe was produced with a component that was "experimental" and would be watched closely by the factory. Just my 2 cents.

[8E45E]

Do you have the parts catalog?

The 'X' might also be part of the complete serial number string which includes wheelbase, GVW rating, rear axle, etc. An example of the serial number plate is shown in the parts catalog on the second or third page and describes the breakdown of the component letter codes.

Craig

[migral23]

Thanks for the couple of replies.
As to Craig's (8E45E) suggestion, I do have a copy of the parts catalog; it's a Fourth Edition, dated August 1, 1949. In it, there is no example (I took that to mean an actual picture of a dataplate from the left seat riser) of a dataplate; only on page VI does it talk of serial numbers, and there it just shows the model series/model year/car serial number combinations. The only mention of an exception is a note that says "The prefix "S" to a car serial number indicates that truck was produced at the factory with certain special equipment....". So from that, there's still no overt explanation of an "X" suffix as is on the truck in question.
Skip Lackie: any thoughts?

[Studebaker Wheel]

Post a photo of the serial plate.

[migral23]

Ah yes, of course, post a photo of the plate. I thought it might be answerable without, but sure, here's a photo of the plate in question:

[8E45E]

In the (much) later truck parts catalogs where they do show an illustration of the serial number plate, an 'X' in the serial number string denotes the type of brakes it has. In the case of a 1963 8E, it would mean air brakes; which was not offered in 1948, but a Hydrovac assist was. Does your truck have a brake booster?

Craig

[Studebaker Wheel]

[QUOTE=migral23;1024707]Ah yes, of course, post a photo of the plate. I thought it might be answerable without, but sure, here's a photo of the plate in question:
[/


QUOTE]

Perhaps the production order from the SNM would give you the answer.

[migral23]

I'll check with the SNM for requesting a Production Order.
And to answer Craig (8E45E)'s question: yes, the truck does have a hydrovac brake booster mounted on the driver's side frame rail aft of the cab. Perhaps that's the answer.

[Studebaker Wheel]

Did a quick search in my M series files and found two other M16's with the X suffix. Attaching one on original invoice from local dealer below. I am sure I could find the answer given enough time to go through all of my M series files (which are extensive). It does not appear to be anything real special. Maybe the dual wheels?

A little known (and surprising) fact: There were more M16's assembled and sold (1941-48) than there were M5s! Total M16 - 61,428, Total M5 - 52,541.

[r1lark]

Wow, the M16 that Richard posted the invoice for -- that sure had a lot of extras/options!

[Skip Lackie]

Mike-
Thanks for the vote of confidence. I think it denotes a weight classification required by the particular state in which the truck was intended to be registered. Pennsylvania required such serial number suffixes on the registration forms for all but the smallest trucks at the time, and probably other states did, too. I was unaware that these suffixes were actually added to the serial plate, however.

[studerex]

Did a quick search in my M series files and found two other M16's with the X suffix. Attaching one on original invoice from local dealer below. I am sure I could find the answer given enough time to go through all of my M series files (which are extensive). It does not appear to be anything real special. Maybe the dual wheels?

A little known (and surprising) fact: There were more M16's assembled and sold (1941-48) than there were M5s! Total M16 - 61,428, Total M5 - 52,541.

[ATTACH=CONFIG]60175[/ATTACH]

What is a fish plated frame???

[TWChamp]

Fish plate is the heavy plate added to the frame to give it more strength.

[Studebaker Wheel]

Upon further review I am now thinking that the X suffix is likely for trucks equipped with the two-speed vacuum shift rear axle. This feature was introduced in mid April 1947 at serial M16-41305. The original invoices I have with the X suffix are all after that date and I see no such X suffix on invoices before that date. Now if Mike will simply confirm that his truck (M16-51492) does indeed have the two-speed rear axle I will be convinced (sort of). If it doesn't it is back to square one! Have original documentation on the two-speed option if anyone is interested.