Question about Cab 12 Chevrolet FAT

[Phil Waterman]

Hi Niels

According to the MB-C1 Manual C-30, C-60 and C-GT all share the same axle gear ratio 7.16 to 1 so a unit swap should be OK from ration point of view.

What is interesting is the track FRONT and REAR

C-30 Front 70" and Rear70 1/2" Tire Size 10:50x16
C-60 and C-GT Front70 1/2" and Rear 69" Tire Size 10:50x20

But as has been said the best way is going to be to look up the parts numbers for the different units. If you are going to acquire reprints of the manuals, parts book you should also try and find a set of the service bulletins as there is a lot of useful information in those as well.

Service Bulletins -B-62 for example has detail information on spring rates and what is interchangeable with what. One of the things that comes out in that is that the 1941 FAT and all 3 tons had 10 leaves and 1950 Load rating while the 1942 which would be Pat 13 it jumps 15 and 2900. (I'm not sure of the number of leaves at 15 may be incorrect.)

CMPs a lovely jig saw puzzle.

Cheers Phil

[Niels V]

Hi guys
Thank you very much for your answers.
I will have to see what it has when I get it home, Sadly I didnt get proper pictures of the front axle on it, only these.
It had, by the way, some very nice rear tires on.

[Bob Carriere]

From the pictures you have just posted your front axle is the lighter model intended for 16 inch rims such as CMP C15a......although the larger 20 in. tires will fit quite well and the gear cluster may have been changed to the 7.16 ratio as it will bolt in.

From my experience the brake drum and all brake components of your gun tractor will not interchange with the brake parts of a C60 front axle.

Bob C

[Niels V]

Here are a couple of better pictures of the axle

[Keith Webb]

In my understanding the front axles for 3 ton payload CMPs were all the lighter (4 7/8") type until the 6" steering ends were introduced sometime in 1942. So the axle shown is correct for your vehicle. The brake drums for the 6" type were a lot wider.
The 4 7/8" type steering ends were then used only on the lighter 15CWT and 30CWT models.

[Phil Waterman]

Hi Niels

The photos and comment are confirming that the axle and brakes are the same or nearly the same as the front axle on my 1941 Pattern 12 Chev 3 ton.

So for more photos of the axles go over to my web site http://canadianmilitarypattern.com/ and look at the section on Pattern 12 or jump directly to the axle page http://canadianmilitarypattern.com/P...eRemoveal.html Remember to click on the pictures if you want a larger picture. If you need more detail on any of the photos just post your question and which photo. I'll be glad to post a larger higher resolution link.

I've been able to find most of the brake parts, the only thing I really have not looked for is brake shoes, but there is a photo of the basic dimensions for the front and rear axles shoes.

Cheers Phil

[Niels V]

Thanks
I will study it