The Stovebolt Site Forums The Shop Area General Truck Talk Identity Crisis - 1946 GMC - 1/2 ton or 1 ton?

Hello fellow Stovebolters, I own what I beleive to be a 1946 GMC truck. The body is definately GMC. The rest of the vehicle seems to be made up of bits and pieces. I need some help trying to identify exactly what I have. The facts I have:
Maple leaf chassis, body made by General Motors Holden (Aust).
Chassis plate chassis = 2520lbs
Gross weight = 5800lbs
ID plate could be wrong.
Front brakes - same brakes as 1/2 ton 6 lug 5-1/2 stud pattern commercial.
Rear brakes - 14"x2" 6 lug 5-1/2" stud pattern drums.
Diff - 10 bolt, single wheels
Wheels - 17"
Engine - originally 216 cu with 4 speed. Now a 235
Rear springs - 9 Leaves
Any help would be really appreciated?

http://photobucket.com/1946GMCidentificationviews

Based on the stats you posted, those actually seem to match a 3600 (3/4 ton).

Small, 6 on 5.5" wheels are 1/2 ton, modern '10 bolt' rear axles are also 1/2 ton. A px would be helpful.

Thanks Dave. This was the other option I had considered. I have posted a link to some photos if you get a chance to look. Regards, Jayde

Hi Ed, this is my dilema, many items such as the stud pattern suggest 1/2 ton. I don't know the age of the 10 bolt or the 14" rear drum brakes, they certainly appear to be inconsistent with the front end. The number of leaf springs also suggests it could be a 3/4 ton.
A link to photos is attached to my orignal post. Regards, Jayde

What is the wheel base of the frame?
center of front wheel to center of rear axle?
1/2 ton should be @ 112" and 3/4 ton 122 or 10" longer.
1 ton should be 10" longer i think.
go measure and well go from there.
Barry

My canadian 1951 1 Ton has a GVW of 5700 lbs. The Canadian trucks had a slightly smaller gross in some cases. I think my gross is less because of the factory tire option and the number of plies.

I don't have the #s here but GMC made long wheelbase 1/2 tons when I get home I'll look .


Pete

In the USA, a series 100 GMC would be a short-bed 1/2 ton and a series 102 GMC would be a long bed 1/2 ton.

Hi Jayde:

I'm not too good with GMC, but I can tell you that my '41 Chevy 3/4 ton has the same 6 on 5 1/2" bolt pattern on both front and rear wheels. AND has the same differential which I believe was unique to the '41 3/4 ton's. If you look you can see the 3 jam bolts and locking nuts used to hold the pinion bearing in place from the back side. This was typical for the 1/2 ton closed drive shaft. When Chevy went to the open drive shaft in the '41 3/4 ton they cut off the snout of the differential and went to an exposed rear universal.

Thanks Pete52, just measured the wheelbase, it is 124 inch. So either it is a half ton with a 41 rear axle or a 3/4 ton. Have you had a chance to check numbers?

8 lug 3/4 and 1 ton rear axles did not come out untill 1947. prior to that 6 lug axles were used on 3/4 ton trucks. I don't know what was used on 1 tons prior to 1947, but 14 inch brakes certainly screams 1 ton to me.

So yes it is certainly possible that you have a Canadian Maple leaf 1 ton truck in it's mostly original configuration. From the pics it looks like you have a sweet truck.

John

On early US 3/4 ton chevys, 14" brakes on rear were optional. 11" front, 14" rear.

Sorry, it's been busy around here I'll check today.

Go to OldGMCtrucks.com and you can look up you're truck it tells you how to decipher the serial # and wheel base.

Pete

I have a Canadian built 46 3/4 ton that we are slowly taking apart.It has 8 bolt 17 inch split rims so I am surprised to see yours are 6 bolt. For a 3/4 ton it has the short box and was set up with a hydralic dump and we found a weigh slip from the saskatchewan wheat pool dated 1980 something.If my memory serves me right your Maple Leaf truck would have come from the Oshawa GM truck plant or posssibly from a plant out west. The canadian Gmc trucks had the chev 216 not the 228 Gmc engine ? Let me know if there is anything on our truck that may help you out identifying yours.
Murray

Thanks John, it is all starting to come together. Until now I thought I had a bit of a mongrel, made up of what ever bits the previous owner could find. It struck me as odd that the front drums (11") were smaller than the 14" rears. It may turn out that I have a fairly rare truck with a desirable rear axle option! I'm feeling much better about the amount of money I am now pouring into it. I will add some more photos of the freshly painted cab and rebuilt/balanced engine etc. Regards, Jayde

Thanks Pete, will do.
Regards, Jayde

G'day Murray, I think we predominantly had the 216 Chev engine as standard equipment on all Chevrolet 6 cylinder imports. It is a very rugged motor and was an up spec from our many rival manufacturers, especially from the UK. Very few 228 GMC engines here that I have heard of though I may be wrong. The issue with the 6 lug was the same, due to the small number of vehicles imported, it was important to be able to have common parts across the product range to reduce the spare parts inventories of service centres. Considering that at the time, Australia comprised of only 8 capital city centres across a country as big as North America, with a population of less than 18 million. Still only 21 million! Hence the difference on Australian imports. Regarding the offer of assisstance with comparissons of parts , once it returns from the painters, I will take more photos and take you up on your kind offer off help. Regards, Jayde

G'day Murray,
The mystery continues. My id plate seems to be a bit dodgy. The chassis number on the ID plate is only 4 numerals with no letters. Do you know if the chassis number is stamped on the actual chassis anywhere?
Jayde

Jayde - the numbers weren't stamped on frames until the mid-50's here in Canada, where your truck would have originated, but note that the trucks were shipped to HoldenGM partly 'knocked down' and as they were sold as Aussie vehicles, it's likely Holden issued the serial numbers ... also looking at those wheels I'd guess they were Holden supplied

Bill

American GMC prewar and war vintage trucks got a number stamped on the frame on the right side just above the front axle. The American number would start out like CC101 for a 1/2 ton short bed, CC102 for a 1/2 ton long bed, CC152 for a 3/4 ton and CC252 or CC253 for a 1 ton.

Going through your pictures, I notice your truck is right hand drive. Pretty cool! I also noticed the firewall is fairly smooth without any ribbing stamped into it. This leads me to believe there was work done to smooth out the firewall, or your truck is using a 1940 cab. The 1940 cab is about 2 inches shorter than a 41-47.1 cab. Some parts interchange between 1939-1947 like doors, seats, windshields. **Edit** The firewall doesn't have the 1940 ribbing either... likely smoothed out.

Jayde
I have not found any #'s on the frame , on ours the info is on a plate easily seen when the passenger side hood is open. I have been playing with my 63 panel truck and the 46 sits neglected.

Thanks to all for your help on the mystery. A little more light has been shed as the truck is now home from the painters. Measuring the chassis and the general configuration tells me it is a 3/4 ton.
-It is equiped with the 2 1/2" spring hangers but has 2" springs with the 1/2 " spacer.
-It has the 1940/41, 3/4 ton light duty 10 bolt differential.
-125" wheelbase
-6 bolt 14" drums.

The more practical problem I have is identifying the diff housing and establishing what parts to purchase for the rebuild. I will add some photos presently. Anyhelp in identifying would be great, there will be a few Coopers Pale Ale in for you (when you visit Australia next).

Now the mystery is, as biggadswingdaddy pointed out, the question of it's age, is it a 1940 or a 1946 or somewhere in between?

Here's the link http://photobucket.com/1946GMCidentificationviews


Thanks fellas.

Great looking truck, you're doing real nice work. I'm a little surprised at the right hand drive. I did not know they even existed. Must be a very rare truck indeed.

Jayde,
Maybe this info might help even though is a Chevy, however, the GMC frame and body should be identical.
http://chevy.oldcarmanualproject.com/chevyresto/4653.htm

Jayde:

I looked at you photobucket. That diff. looks exactly like mine did. You will find that a 1955 second to 1962 one half ton diff will bolt right in. A while back I did a tech tip on the swap.