I've been doing a search in this board under "48 VIN," and while many posts have come up, none have answered my specific question.

One of my '48s has *88RT**62355* on the firewall tag.

That cab is mounted on, what I interpret to be, a '41 frame, but that's incidental to my question.

My understanding is that the first "8" indicates year model, the second "8" indicates V8, but I can't figure out what the "RT" is telling me. The final piece of data is "SP" in the "BRANCH" field, indicating the Saint Paul assembly plant, if I'm correct.

(Both my trucks came from the upper Midwest, MN and ND.)

I would be grateful for your thoughts.

 

The Ford Serial Number (VIN) has the following makeup:

8 1948
8R V8
T 1 ton + truck
62355 Production Number

 

The SP Branch code is for St. Paul assembly. The T in the serial number would denote the truck being an F5 Truck. F4's are identified as TL, and F6's as TH. F1-3 pickups are C, D and Y in that same space.

 

TH and TL were not used as distinctions in the VIN even though those TH and TL distinctions are used elsewhere in Ford documentation. Only a single digit was used. My '49 F6 only has only as T.

More reading: Early Ford Serial Numbers For Cars and Trucks Manufactured for the USA Market from 1932 to 1953

 

Thanks to 52_merc and bmoran4. This helps greatly. My other truck is also an F5, according to your interpretation but over time someone had installed a 2-sp rear axel w/granny box and bobbed the frame to pull trailer houses. What an abortion but, the skins are good save for the standard door bottoms and cab corners.

Thanks again for your help.

 

Sometimes. Either or Both. It really depended on the assembly plant as near as I can tell.
My 50 F4 serial number is 97HTL ******
My F6s just use 98RT

 

Re: Frame.
I've found 48 trucks retained some of the earlier truck frame/parts, likely because they were still on the production line and the fit the new frames. Ford had a penchant for making running line changes. Also the 48 truck line came out with the new sheet metal and new engine on January 16, 1948.

 

Interesting... I don't recall coming across that before, either in person or in documentation. But it isn't unheard of for some odd variances...
​​​

 

I know I've seen 98MTH serial prefix's for 254 equipped F6's, but finding the evidence is another matter.

 

Because my curiosity got the best of me - out of 1240+/- 1949/50 trucks in the data base, I found the following serial number prefixes.
7 - F4 marked 97HTL and one indicating KC as the branch
9 - F4 marked 98RTL and one indicating HP
20 - F5/6 marked 98RTH with several plants SP, SOM, KC, CH
20 - F5/6 marked 98MTH with CH on one
2 - F6 marked 97HTH

1948 out of 330 trucks, only noted 2 F6 marked 98RTH with one indicating HP as the branch.

edit added: All other F5/F6 were only marked 98RT

Keep in mind most of these have been reported by the owners so accuracy could be questioned I suppose.

 

You might enjoy wandering thru this thread

https://www.ford-trucks.com/forums/4...n-cut-off.html

 

This is really getting interesting.

So, if I'm digesting the comments correctly, it's possible that my "F5," the dual w/2-sp axle, may be an F6 after all? The cab actually has "F6" badges on both sides.

 

The Eaton 1350 was used both on the F5 and F6. Check your glove box tag. That should have more series information. Also, see if you can find the VIN on the frame to see that it matches the cab.

 

Neither of my old trucks have stickers/labels on the glove box doors. They were farm trucks that saw hard use and the one with the Eaton axle, as I mentioned earlier, had been used as a trailer house puller. That's possibly some of the worst duty a truck can be subjected to.

The s/n on the dually frame indicates that it's a '48 F5, most likely: *88RT**21123*. Interestingly, the firewall tag looks to be original though it has no s/n data; only patent numbers. Just for purposes of keeping everything straight, I refer to this one as the "white" truck though it's actually green under a white "floor mop" paint job.

The other truck looks to be chrome yellow though the firewall is red (go figure). I call that "the yellow truck." I think you'll understand why in a moment. The yellow truck is the subject of my original post in this thread.

As mentioned originally, the cowl tag number on that one is *88RT**62355* YET, the frame number is "21C-50878." No stars in the number nor other punctuation. I believe that frame is a '41 model.

Incidentally, I had no trouble at all getting the white truck registered but the yellow one is another matter, though the nice lady at the tag office in Shelbyville has "coached" me on a solution.

Let me just say again, thanks to all for showing an interest in my puzzle and adding your thoughts. I'm truly grateful.

 

Hopefully this link will take you to the forum search i did in the 47 and older forum with the words VIN or Serial Number
https://www.ford-trucks.com/forums/s...rchid=33307950

In general if a truck from 32-42 came with a V8 the serial number will begin with 18-(1234567)
A 6 cylinder truck from that same time period will begin with 1GC-(1234567)

The number string is actually the engine number and is consecutive during the years 32-42
Civilian production all but stopped during WW2 and began again in 45 using the number prefix 599 so there is a number shift but it was still the engine number, not the "vin" number.
"VIN" numbers started in 48 but were referred to as serial numbers until the mid-60s.

This is a quick thumbnail sketch and I recommend reading threads on the 47 and earlier forum for more complete info.
Tim