Chevrolet 1533X2 30-cwt trucks

[Hanno Spoelstra]

From Clive Law’s “Drive to Victory”:

[Simon Theobald]

Dear Hanno, I wanted to thank you and everyone else who contributed to the information I asked for about the truck in my Father's WW2 photo. All of the great information helped me model a version of the picture I showed you. I don't think it will be the most accurate but gives a flavour of the right truck..... and likely the last I ever attempt! Thanks again and stay safe from a "locked down" England!!

[Tony Smith]

Well done!

[Bob Carriere]

Very well done indeed.

Bob C

[Hanno Spoelstra]

Hello Simon, that’s a very nice tribute to your father!

Happy to hear the info on here was of help.

[Simon Theobald]

Thanks all for comments!

[Charlie Down]

Hi Bob,
I'm trying to get details of the bumper brackets. It looks like the 1533 and 1543 had solid brackets that raised the bumper to allow the starting handle to pass through the bumper, not the lower spring style civilian brackets. Is there any information in your 1543 parts list about these brackets or is the 1940 edition too early for this detail.
It also appears that there were supporting bumper rods outboard of the brackets that attached to the bracket on the chassis end and went through separate holes in the panel below the grill, before attaching to the bumper.
Trying to clear up this detail.

Many thanks

[David Herbert]

I would have thought that the reason for raising the bumper was to get it further from the ground as the vehicle was to be used cross country. That would have required the starting handle hole to be in in the bumper rather than above it. There would have been no motivation to have the starting handle go through the bumper otherwise.

David

[Charlie Down]

Sorry, that was badly worded on my part, the bumper was raised to give greater ground clearance, which resulted in the starting handle hole now locating in the top of the front face of the bumper.
Apart from the 1500 series of Chevrolet trucks these bumper brackets don't seem to have been used on other trucks.

[Bob Carriere]

Although the part book No 167 does list front bumper (7.825) in the index it is NOT shown either as a picture or a listing in the parts section...... lowest number in the bumper listing is 7.831 ...... bar, front bumper than goes on o the various brackets an rivets/bolts.

The 1940 book no 154 also has a bumper section but starts at 7.831....no diagram and 7.831 is Bar, bumper 2 required...... the rest is all brackets info

Engine crank is 0.239 is listed by itself with no additional info......

The books are like bibles written by different apostles....more or less the same but not good enough by themselves to get you to heaven!!!!!!!

Stay healthy

Bob C

[Charlie Down]

Thanks Bob for your ecclesiastical reply!
I doubt I'm going to heaven anyway!

Its a shame the parts list isn't more forth coming, maybe a bit early although the 1500 series were, I presume, MCP, not purely civilian.
Something will most likely come up.

Ironically the 1972 Tamiya kit had the correct parts in it (although missing the support bars), so I presume the kit was based on a reproduction. If I knew who owned the truck that it was based on I could contact the owner and get photos.
Any ideas?

[Bob Carriere]

Heaven is full of CMP mechanics who earned the relaxation.....

Hell is full of the engineers who designed them...........

Are you looking for the brackets associated with the military whatever
C channel bumpers or the civilian ones which where below the crank????

I have a 42 HD Chev. GM in the back field that has a particularly heavy civilian bumper that I have only seen once....... would have to dig it out of the snow but it is not impossible. Only about 18 inches deep before the next snow fall.

Do you know if they have a special vaccine to go to heaven????

Stay healthy.

[Charlie Down]

Hi Bob,
I'm looking for the brackets that raised the front bumper. It was a MCP/military bumper with 4 bolts through each bracket and bumper on each side. Some vehicles used these 4 bolts to attach a D ring plate. A bush bar was standard (So MCP), and the bumper was the heavy duty high 'C' channel bumper with a radiused curve along its length. My research show that the bracket at the chassi end had a mounting for a support rod that went through 'new' holes in the panel below the grill at an angle and attached to the bumper. If you look at the bumper head on you'll see 2 welded bolts either side of the bush bar where the rods connected. I've only seen it on 1500 series Chevrolets, all the 1533x2 of the LRDG, and some 1543 trucks.

[Colin Alford]

Gents,

Ref the question: Did 1533X2 use a two speed rear axle?

Yes, it did. Please see the attached images.

I didn’t realize I had access to information regarding these vehicles or I would have contributed earlier.

Colin

[Charlie Down]

Colin, that's brilliant.
There's been controversy about this feature for years, and that's one more ticked off the list.
Just need to find out about the Bumper brackets and the fuel tank cover for the CMP seats (most LRDG 1533X2 trucks had these seats, not the bench seats).

[Andrew H.]

Originally Posted by Charlie Down

the bumper was the heavy duty high 'C' channel bumper with a radiused curve along its length.

Charlie, by "radiused curve" do you mean curved throughout? If so, that cannot be right, as the wartime photos show the 1533X2 bumpers to be straight, with a angled bends at each end.

[Tony Smith]

Originally Posted by Bob Carriere

TONY........ I have a 1543X2 parts list, issued November 1940 ( no 167) and it does list the Eaton 2 speed axle....... but blank luck on the 1533!!!!!!

Cheers

The Major Assemblies manual shows that it it the same rear axle assembly (and subsequent superceding numbers) used on both trucks. Very heavy duty for the 1533! This might help someone seeking to scrounge parts from a donor truck to make a 1533 replica.

I see that the model code for both 1533 and 1543 are the only trucks with the two speed specified. I wonder if the xxx3 indicates "two speed" axle?

[Grant Bowker]

Originally Posted by Tony Smith

The Major Assemblies manual shows that it it the same rear axle assembly (and subsequent superceding numbers) used on both trucks. Very heavy duty for the 1533! This might help someone seeking to scrounge parts from a donor truck to make a 1533 replica.

I see that the model code for both 1533 and 1543 are the only trucks with the two speed specified. I wonder if the xxx3 indicates "two speed" axle?

It might be like the use of the same parts being used throughout the CMP range. Only one part to inventory and not enough weight or cost saving to justify the added trouble/cost of having two sets of parts.

Statistically, the number of spares/truck required to keep a fleet serviceable goes down the larger the fleet size of identical trucks (or airplanes, ships or widgets) you are maintaining since the odds of them all failing at once get smaller as the fleet gets larger. Put another way 1 failure is 100% of a single vehicle fleet but the same failure is only 1% of a 100 vehicle fleet.

[Tony Smith]

Originally Posted by Grant Bowker

It might be like the use of the same parts being used throughout the CMP range. Only one part to inventory and not enough weight or cost saving to justify the added trouble/cost of having two sets of parts.

Exactly. And for the same reason, I would hazard a guess that the Chev parts 5806664 and 5824253 have precisely identical equivalent parts with Ford part numbers used in the FC60L. Same Eaton diff centre, same track and spring centres and same 8 lug hubs for WD wheels.

[Bob Carriere]

Hi Tony

in my 1940 GM army Parts list Jan. 40........15 is the series....they had ....13 half ton....14 one ton.... 15 2 tons and 18 2 ton cab over.....

Notice the absence of 3/4 ton.....the designation Commercial abd Utility seems to have disappeared at least in the army books....
-31 was a 2 ton Chassis with flat face cowl ...133 wheel base
-32.................................... windshield cowl 133 wb
-33...............................with cab 133 wb
-35 panel delivery 133 wb
jumps to
-41 was Chassis with flat face cowl....158 1/2 WB
-42 was a 2 ton 15 series with Chassis and windshield cowl... 158 1/2 WB
-43 is the Chassis with cab ...158 1/2 WB

So 1533 WA is a 1940 133 wb with cab...... the X2 was special eXport????

Then you have all the old Letter designation.....

A 1939 appropriated from local Egyptian source would have a
VA and a VB the only ones in the 133 wb

BUT they did have some odd ball smaller model used by officers and as medical trucks which could have been JD and JE as 3/4 Ton
with a 123 in. WB
I believe that the Windsor made Canadian "Water Fall grill" for LRDG were a real mix of odd ball parts that fitted the contrqact requirements.

The 1940 series has a "WA" series `1 1/2 ton with 133 WB

There are no 1942 Chev trucks with 133 inch WB......BUT they do have a
134 1/4 in

...and as odd balls go they may also have had 1938 chassis reproted as 1939 as we know some 1939 VB are registered as 1940 evenrthough they sport 1939 instrument clusters......

But I have seen more than one Australian contract cab 13 C60 with 16 inch running gear, long wheel base with 1940 civilian rectangular instrument cluster........

Than you had forward repair stations told to fix shot up trucks from the piles of blown parts they had.....

...and a book printed date of Jan 1940 must have been in the working stage for at least 3 to 5 months......

Then you have the Maple Leaf which is essentially a HD Chev as
series 16 with 2 1/2 ton capacity .....16-61 Chassis and cowl at 133 3/4 WB
....-62 with windshield at 133 3/4
and -63 chassis with cab at 133 3/4

Then the big boy a 16H as a 3 ton using the 61,62,63 numbers which I believe used the low oil pressure 235..

The point of all this is if you are reproducing one fo the first 30 some LRDG adapted locally by Egyptians shops you do have quite a latitude of freedom as to what you will use....... even the cute UTE conversion if they could get there hands on it....... Look at what they did to the beautiful woody station wagon that Montgomery used....... certainly was not done for low bridges ....

Now the Canadian made LRDG was more consistent but does looklike a 1941 front end............. and all were eventually field mofified either by design or by accident when shot at.....

Imagine how good a cooking surface the small hood of a cab 11 would be on a camping trip...... and you do not really need it to run......

Same for doors, tops, windshield and bumpers....all dead weight.

The LRDG may have been the early stage or precursor of "hippies"

[Grant Bowker]

Again by parallel to CMP, Ford and Chevrolet may have used different rear axles. The ones shown appear to match Chevrolet casting style (not a Ford split axle). I don't know how Ford handled 2 speed axles - whether with a split housing, a GM style banjo or a pure "supplier" axle (Eaton, Timken, Spicer etc.). I will try to dig into this more later.

[Colin Alford]

Gents,

While I have never been particularly interested in MCP vehicles, I now realize that I have access to some manuals that can very likely answer some of the questions that have been posed on this forum.

The reason it took me this long to realize is that I looked at these as CC60L manuals, and didn’t make the connection to the Chev model numbers 1542, 1543, etc.

I will attempt to provide some assistance.

Colin

[Colin Alford]

Since this thread is primarily about 1533X2, but no-one seems to have a parts manual for it, let’s start by using the Major Assemblies book to see what vehicles shared the same major components as 1533X2.

Here is the data regarding engines for Chev MCP vehicles.

Both 1533X2 and 1543X2 used engine assembly 5269525. It appears that the significant difference between this engine, and other MCP engines, was a six-bladed fan, with a spacer between fan and pulley.

[Colin Alford]

Transmission,

While the transmission was visually similar to other CMP and MCP types, if we look at the bottom of the conversion chart, only 1533X2 and 1543X2 used the same speedometer drive gear.

[Tony Smith]

Originally Posted by Grant Bowker

Again by parallel to CMP, Ford and Chevrolet may have used different rear axles. The ones shown appear to match Chevrolet casting style (not a Ford split axle). I don't know how Ford handled 2 speed axles - whether with a split housing, a GM style banjo or a pure "supplier" axle (Eaton, Timken, Spicer etc.). I will try to dig into this more later.

The Eaton 2 speed differential is of a "Banjo" design, regardless of it's intended vehicle; Chev, Ford, Dodge, Bedford, Leyland. It's still getting about today with some refinements.

[Colin Alford]

Front axle.

While there were 3 possible front axles on 1533X2, they match the last 3 (of 5) types used on 1543X2.

[Colin Alford]

Steering gear,

1533X2 and 1543X2 used the same three types of steering gear. 1542X3 used only the last two types as the others.

[Tony Smith]

Originally Posted by Colin Alford

Transmission,

While the transmission was visually similar to other CMP and MCP types, ... only 1533X2 and 1543X2 used the same speedometer drive gear.

Because the Speedo Drive gear ratio has to be related to the specific Differential Ratio and tire size.

1531 and 1541 had 6.16:1 gears and 17" wheels
1542 had 6.16:1 gears and 20" wheels
1533 and 1543 had Eaton 2 speed diff and 16" wheels.

The Eaton final ratio was dependant on the particular ring and pinion gears fitted with a fixed reduction in the 2 speed gears. Typical ratios of the 40's were 5.83/8.11 and 6.33/8.81 ratios. Note that the Hi ratio in either of these combinations is not the same as the 6.16 of the Chev differential, so a unique speedo drive gear ratio has to be use with the Eaton.

Now if Bob Carriere would be so good to look in his 1543X2 parts manual, we might determine the actual diff ring/pinion ratio.

[Colin Alford]

That exhausts the information available in the Major Assemblies book.

My read on this information (and the information/study presented above by others) is that “Major Assembly-wise” 1533X2 was essentially the same as 1543X2, but there were definite differences in wheel-base (and therefore frame), cab style, and cargo box.

My inference is that Parts list CC60L-01, and Driver’s Handbook CC60L-HB1 (which both cover 1543X2), are probably reasonable reference materials for mechanical systems in 1533X2 in the absence of the correct manuals.

[Colin Alford]

Tony,

The parts book doesn’t seem to give a good indication of the rear axle ratios, but see the attached image from the Driver’s Handbook.