M/H Ford 3a FAT (Aust) question

cliff · #1 10-09-06, 23:03

I have been collecting information and measurements on the Australian 1941 Ford Marmon-Herrington gun tractor with the ultimate aim to do a 1/35 scale model of one.

Now apart from the M/H conversion to the chassis I believe that the front Mudguards, bonnet, grill and firewall/cowl/windscreen frame are the same as the standard 1941 truck and the only difference was in the doors and back of cab area.

Is this correct?

Can anyone tell me if the doors are the same width as the standard doors and the cab from the door hinge pillar to the back of cab are the same as a standard cab.

Or even better is there someone out there that maybe has one can give me some basic measurements of both the cab and the rear body?

Thanks in advance

Cheers
Cliff

Photo is courtesy of AWM and shows the model I want information on.

Ian Pullen · #2 11-09-06, 09:28

Cliff, try John Bellfield. If I remember rightly, he has one on the boil in Melbourne. In addition the Arty Museum (4 Fd) in Townsville also has one in progress. Good luck......
CHEERS IAN

Tony Smith · #3 11-09-06, 10:05

While based on a Truck chassis, the cab back is not a cut down truck cab. Some pics on the way to you, Cliff.

cliff · #4 11-09-06, 10:32

Quote:

Originally posted by Tony Smith
While based on a Truck chassis, the cab back is not a cut down truck cab. Some pics on the way to you, Cliff.

Tony thank you for that. I did have a feeling it was totally different to the standard cab from the door pillars back. Thanks for the extra photos.

Thanks for your info Ian I will try and contact the Townsville people and ask if they would do some measurements for me.

Cheers
Cliff

Keith Webb · #5 11-09-06, 11:23

Quote:

Originally posted by Tony Smith
While based on a Truck chassis, the cab back is not a cut down truck cab. Some pics on the way to you, Cliff.

Who's the codger in the driver's seat?

Tony Smith · #6 11-09-06, 11:42

Quote:

Originally posted by Keith Webb
Who's the codger in the driver's seat?

Someone who's

Keith Webb · #7 11-09-06, 13:01

Quote:

Originally posted by Tony Smith
Someone who's

I would be too!

Was that taken in Na Zillun?

Tony Smith · #8 11-09-06, 14:46

Quote:

Originally posted by Keith Webb
Was that taken in Na Zillun?

It was!

Speaking of New Zealand Airshows and such, I note that the ex-Wanaka Spitfire will make it's Australian airshow debut this weekend at Temora, in the company of Temora's other Spitfire. This is being promoted on TV as the only time 2 privately owned Spitfires have flown in Australia. Will Keefy be there to capture this moment?

Keith Webb · #9 11-09-06, 21:05

Quote:

Originally posted by Tony Smith
It was!

Speaking of New Zealand Airshows and such, I note that the ex-Wanaka Spitfire will make it's Australian airshow debut this weekend at Temora, in the company of Temora's other Spitfire. This is being promoted on TV as the only time 2 privately owned Spitfires have flown in Australia. Will Keefy be there to capture this moment?

Guess who's doing some air-to-air filming later this week?

I also set up some timelapse filming of the reassembly.

The new Spit is a Mk XVI which test pilot Steve Death said was remarkably similar to the Mk VIII they've had for a while. I think the registration is VH-XVI.

Ian Pullen · #10 12-09-06, 04:37

Mate, I hope the weather is against ya ...........................................

Keith Webb · #11 12-09-06, 10:18

Quote:

Originally posted by Ian Pullen
Mate, I hope the weather is against ya ...........................................

We'll see... more likely events will be because it's always hard to try to do anything before a flying weekend.

Hanno Spoelstra · #12 13-09-06, 10:38

Quote:

cliff wrote on September 13th 2006 13:21:
Do you know if the M/H front axle is different then say the Ford 4X4 CMP front axles?

If so do you have any photos, details etc of these axles?

The reason I am asking is that I intend to build both an Aust #9 Ford GT as well as a Ford M/H 3a GT and as I intend to scratchbuild the axles was wondering if I could use the CMP front axle or would have to build another.

Hi Cliff,

As far as I know M-H made front axles by adding steerable joints to standard Ford rear axles. Many different M-H front axles were made, depending on the type of chassis being converted (1/2, 1, or 1-1/2 ton).
Especially in 1:35 scale outward appearance, I think the 3-ton CMP front axle is very, very similar as the converted Ford/M-H axle fitted to the Australian gun tractor.
I've posted some pictures of M-H axles in my G503 album that might be of help (but I don't know what year/weightclass these are).

Looking forward to seeing your models!

Cheers,
Hanno
Marmon-Herrington Military Vehicles

P.S.: The link between CMP trucks and Marmon-Herrington is closer than you might think, as per The Design Record, Vol. 4, p. 27:

Quote:

Marmon-Herrington's expertise on all-wheel drive vehicles was also called upon when the Canadian automotive industry geared up for war production: "Immediately after the war was declared, the Ford Motor Company of Canada were charged with the responsibility of developing a 4x4 truck for army use. Obviously, they had very little experience in this field. Consequently they went to the Marmon-Herrington Company, Indianapolis, who in peace time supplied conversion material to convert Standard Ford 4x2 trucks into 4x4 models for various commercial peace time usage. These joints were unsuitable [the weight of the more or less cab over engine design and heavy army wheels/tires put too much load on the front axle joints.] To solve this problem, "Bendix-Weiss and Rzeppa joints were chosen by General Motors and Ford respectively [They later realized that the "Tracta" type was better but they were already tooled up with the above types, so left it as it was.]

cliff · #13 13-09-06, 11:03

Thanks for that Hanno. I feel that at 1/35 scale the differences will not be noticed.

Cheers
Cliff

Tony Smith · #14 13-09-06, 16:04

The obvious difference that would be apparent in 1:35 scale is that the differential on a M-H is centred-left on the axle, while the Ford CMP's are centred-right. Less obvious, at the swivel housing the CMP swivels are bolted on to the axle tube, and the M-H is tapered and welded, very similar to a Studebaker US6 Timken (are they the same?):

cliff · #15 13-09-06, 23:02

Quote:

Originally posted by Tony Smith
The obvious difference that would be apparent in 1:35 scale is that the differential on a M-H is centred-left on the axle, while the Ford CMP's are centred-right. Less obvious, at the swivel housing the CMP swivels are bolted on to the axle tube, and the M-H is tapered and welded, very similar to a Studebaker US6 Timken (are they the same?):

Ah but being the clever fellow I am I will cast the basic axle and put the spring plates on afterwards. That way I just have to turn the axle upside down for the Ford M/H.

Thanks Tony that is good to know and something I honestly had not picked up on.

Cheers
Cliff

Rob Beale · #16 14-09-06, 11:10

but I have compared the brake backing plates on three totally different vehicles and found them identical, except for the number of mounting holes: a C8AX, a Ford M/H and a Ford GTB. Brake cylinders were the same (and maybe brake shoes too I think.)

So there certainly was cooperation.

Rob

David_Hayward (RIP) · #17 14-09-06, 14:30

In1940 the DND contacted McKinnon Industries Ltd, the GM of Canada subsidiary, nakers of axles and radiators as well as AC and Delco components. They were asked to design new 4-wheel drive trucks, and it would appear that they called on GMC expertise in the Pontiac, MI plant, who were using Timken-Detroit axles and transfer cases.

Hanno Spoelstra · #18 14-09-06, 15:52

Here's a pic of Cliff working on his Ford cab...

David_Hayward (RIP) · #19 14-09-06, 18:33

As regards brakes and wheels, there was indeed a lot of cc-operation from 1938, and it appears that the designers from al sides had problems with fitting the ize of brakes required for military vehicles to the standard truck wheels available at the time.

Turningto M-H and Timken, this seems plausible to me as it appears M-H used Timken-Detroit components as did GMC. Some GMC, Chevrolet and export Oldsmobile trucks also used Timken axles in addition to Chevrolet ones. Would be interesting to get definitive answer.

cliff · #20 14-09-06, 22:01

Quote:

Originally posted by Hanno Spoelstra
Here's a pic of Cliff working on his Ford cab...

LOL I love it........sigh if it was only true and that truck was sitting in my garage

cheers
Cliff

Hanno Spoelstra · #21 16-09-06, 12:22

Quote:

Originally posted by David_Hayward
As regards brakes and wheels, there was indeed a lot of cc-operation from 1938, and it appears that the designers from al sides had problems with fitting the ize of brakes required for military vehicles to the standard truck wheels available at the time.

Turningto M-H and Timken, this seems plausible to me as it appears M-H used Timken-Detroit components as did GMC. Some GMC, Chevrolet and export Oldsmobile trucks also used Timken axles in addition to Chevrolet ones. Would be interesting to get definitive answer.

For what it is worth, this is how Marmon-Herrington advertised about
their co-operation with Ford Canada:

(click image for large size scan)

H.

Tony Smith · #22 17-09-06, 12:27

Quote:

Originally posted by Tony Smith
Less obvious, at the swivel housing the CMP swivels are bolted on to the axle tube, and the M-H is tapered and welded, very similar to a Studebaker US6 Timken (are they the same?):

A comparison of the Studebaker Timken axle, top, and the CMP front axle, bottom. As David has pointed out previously, the Timken axle was initially trialled in CMPs, but was found to be too weak for the cab-over design. Here you can see the difference in thickness at the swivel housing ends and that the Timken diff housing has less reinforcing webs in the casting.

David_Hayward (RIP) · #23 17-09-06, 17:27

I have conjected from evidence, but never proven, that McKinnons license-built the Timken-Detroit design. If taht is so, then they would have added the requisite strengthening ribs. We know from casting marks that GM produced the castings so this makse sense to me.

I have also conjected that experience learned from the CMPs was sent across to Pontiac, MI, who were responsible for US military GM multi-drive trucks i.e. GMC then Chevrolet. Chevrolet's Axle Plant then prodiced components along with those bought in from Clark, Wisconsin and Timken. I note that some transfer cases were "GMC". This must have been from the ex-Northway plant, GM Truck Plant No. 7 in Detroit that produced axles for Chevrolet.