The Stovebolt Site Forums The Shop Area Name that part ... 1946 GMC 1/2 ton long bed torque tube ext?

Hi All, I have been parting out my 1946 GMC 1/2 ton long bed truck and was wondering the proper name or part number for the extension assembly for the torque tube. Full disclosure, I am wanting to sell it and want to list it properly as it probably is pretty rare. Or not.
Thanks in advance.

Roscoe - Can you provide more info on your trucks model number info? I don't have any GMC Parts books to cover the 1941-46 period and an initial review of Chevy books doesn't show any torque tube extension unit like yours that I could find. Chevy info shows only one 1/2 ton truck size. No long bed.

Hi Dan, according to the truck plate; the model is CC 1 02, and the serial number is 19467P, the maximum gross weight is 4600 lbs, the horsepower is 76 at 3000 rpm. General Motors Truck and coach division, Pontiac, MI. I see that Jim Carter truck parts lists a Drive shaft extension shaft for GMC only with part number ME470 for 1939 to 1954 GMC long bed 1/2 ton truck. I believe that shaft maybe inside this housing. I didn't take it too far apart as it is pressed into a bearing.Thanks

Good morning Roscoe. After a catch up on sleep last night , my brain reminded me that I had some recently acquired GMC Parts Book additions to my Stovebolt Library that I hadn't gotten to get into yet. I found I do have a 1945 GMC Parts Book that covers your model, so dove into that to find what I could on your drive shaft part.

A little lead in on the Model info snagged from the book shows GMC offered a CC 101 1/2 ton with a 115" wheelbase (standard bed) and your CC 102 1/2 ton with a 125-1/4" wheelbase (your long bed) for the 1941-46 model years.

The parts book shows Propeller Shafts under Parts Group 18, with detailed diagrams of the driveshaft assembly, including your parts, plus a parts list of the components making up what you have. The diagram below has a red box outlining your pictured "SHAFT ASSY. - propeller, front...", which would have originally included the front ball assembly that attaches to the output end of the transmission. At least for the 1945 produced trucks, it is listed as "2102076", which applies to a specific group of 1945 CC Serial numbers. That number may or may not have changed for the 1946 Model year, but the basic description of the part would remain the same.

For the purpose of listing your part, hopefully in the Swap Meet Truck Parts for Sale forum, you could call it a:

"SHAFT ASSY. - propeller, front: less the forward transmission ball assembly that fits 1946 GMC CC 102 long bed trucks"

Hope this helps you out sir.

WOW Dan, I'm blown away at the information you supplied. This is pretty close to what I have. The difference is that the truck has a 4 speed transmission that didn't have a u-joint on the tail like most 3 speed transmissions do. The extension assembly went directly into the transmission and was bolted to a cross member support that had the ball assembly attaching to the torque tube. So my 125 1/2 long bed truck still only has 1 ball assembly on the drive line(propeller shaft). This might be a unicorn assembly, that's why I posted here as I haven't been able to find the exact parts books. I'm going to keep digging through old books, maybe GMC used the same setup for 47 or later trucks. It will take me a little while to clean the assembly up and get it listed for a fellow Bolter to use. Thank you very much for posting what you found. Andy

Andy - Very interesting info on your "4-speed" set up. If you still have that, I'd love to see some pictures of the transmission overall and output end where this unit slides inside. On the '47 model year trucks, if GMC did the same as Chevy, there is an early '47 that looks the same as the Art Deco '46 and a later '47 that begins the new AD body style.

Interestingly enough, my brain must have been still a little foggy this morning. When I looked at the book again, I found in the very back the back cover actually has an inset pouch. In that pouch I found Change Notices 1 through 5 with a date stamps of NOV 1 1945, FEB 1 1946, APR 1 1946, JUN 1 1946 and JUL 1 1946. Each with from 2 to 5 pages of changes to part numbers listed by Page, Group and Item as well as other data like truck serial #s the part applies to.

All this leads me to want to dive a bit further into the recently acquired GMC books to see what I might dig up. I'll let you know what I find.

Dan: My GMC Master Parts Book 1939-1954 has 2102076 listed as:

"102AC, CC and EC 1940 AC. Front. 8 21/32" Long. 17 Long Splines. Incl Collar."

As you know, 102 is the long wheelbase 1/2 ton truck model.

I don't understand why it calls out AC, CC and EC models and then specifically says "1940 AC."

Appreciate you adding to the information Bill. It seems this was used on the 102 Long Bed models then, including Andy's '46. I also found in my new to me books both a 1939-40 and 1939-41 GMC Book of Parts. When I get a chance I will look and see if they have anything that relates to that weird "1940 AC" mention in your book.

Hi Dan, After looking closer at the transmission by removing 80 years of crud, there is another u-joint right off the transmission. I should have cleaned it up before inquiring on the extension propeller shaft. I will try to attach a picture of the my 4 speed transmission. Sorry for the misdirection after all of your research.

The picture of the front propeller shaft that Dan posted shows two setups, a 1st series 39 and a 2nd series 40-46.
102AC, CC and EC 1940 AC. Front. Type C-8 21/32" Long. 17 Long Splines. Incl Collar. 2102076
102 1939 AC. Front. Type D-8 21/32" Long. 10 Splines. Incl Collar. 2076882

jimgmc - Thanks for the clarification. I'm still getting used to deciphering these early GMC "Book of Parts" and appreciate the help. Is there a complete assembly part number that represents the entire unit from transmission output to torque tube?

Andy - Just my opinion, but if you intend to offer the long bed specific "front propeller shaft assembly", I would suggest including the removable ball section w/front yoke and u-joint (parts still on the transmission) as that's all part of the stuff connecting the transmission to the torque tube.

No

That it most commonly called an intermediate shaft. Sometimes referred to as a jackshaft. The front ball collar should be included with the unit as it does not interchange to other applications. These units were specific to the GMC 1/2 ton long bed. The condition of the internals will help determine the value. The only was to assess that is complete disassembly and cleaning.

I'm on the way to pick up a rolling 1/2 ton GMC long bed frame this weekend that has a similar item, only it's attached to a Hydramatic transmission. I'm not sure if the application would be the same or not.
Jerry

What year is the HM equipped truck Jerry? If stock, I should be able to look the part number.

1953, supposedly. Pics are in the "freebies" forum in Grigg's thread.
Jerry

Jerry: 1939-53 GMC Master Parts Book lists one shaft specifically for HydraMatic equipped trucks. Part number is 2293665. But it is lumped together with 7 other shafts that are described to be around 60+ inches long and a drawing of a traditional driveshaft, so I suspect it isn't what Roscoe (the OP) is looking for.