Chevrolet 1533X2 30-cwt trucks

[Charlie Down]

Colin,
That's fantastic!
Never thought I'd see this in such detail. This looks like there was no hole in the cab floor to activate/control the PTO pump, just this simple pullout lever to engage it. Or maybe both?
The question remains for me, what other details have you got of this series of trucks.
I posted photos of the 1542/3 bumper brackets kindly provided by Dave Ashby, which shows a modified grill where the bumper brackets come out the front panel. The modification gives a larger opening for the military style bumper I presume. Really keen to see any details of this if you have them. I've checked my LRDG 1533X2 photo's but can't see whether this detail is on the trucks, its just an area that was hidden by the bumper or stowage. Any help massively appreciated.

[Colin Alford]

Charlie,

The parts lists have very few useful diagrams in them. Most of the diagrams are generic and in many cases they illustrate parts for completely different vehicles. The best (worst?) example is the fuel system. The illustration is actually for the CMPs and is absolutely incorrect for the MCP trucks. The only useful purpose these illustrations serve is to provide Group Numbers to find the correct part numbers in the manual.

Unfortunately there are no diagrams of the bumpers or grilles. While the majority of the Grille is the same between 1542X3 and 1543X2, the Shell Assembly - radiator lower, is different, which is likely to accommodate the raised bumper on the 1543X2.

[Colin Alford]

In my spare time for the last couple of weeks, I have been attempting to understand the differences in the Canadian Chev MCP trucks, and to be able to recognize the differences in images.

While there have been various opinions on the correct ID of this truck, I believe it to be a 1543X2 with 10.50 x 16 tires built before serial number 1154305001 (translated to the 5001st model 1543 built in 1941).

While the axles, wheels and tires are missing, it has the widened fenders indicative of the fitting of 10.50 x16 tires, it has the remains of one of the unique headlights which were fitted to the early 1543X2 with 10.50 x 16 tires, it has the remains of the spare tire mount as fitted to these early vehicles, it has a complete cab which excludes an ID of 1541 (flat face cowl), or 1542 (windshield cowl).

We can see the (upside down) bumper with attached Extension - front bumper frames, which is missing the holes for the Guard assembly, radiator crash (which is correct as these were not fitted until after serial number 1154305001), and this bumper also doesn’t have the large holes near the ends for the Reflector and Bracket assembly which were only fitted between serial numbers 1154305001, and 3154300001 (the first vehicle in 1943).

To me, the only obvious modification performed in-theatre, is the addition of the sand-mat holders on the fenders.

[Colin Alford]

To my eyes, this vehicle is also a 1543X2 with 10.50 x 16 tires built prior to serial number 1154305001. Most of the ID features are the same as those listed above. The obvious in-theatre modifications are the bars attached across the driver’s door, and the chopped cab.

The bonus of these images are the missing front bumper which seem to be the best images I have found which show the area behind the raised front bumper as fitted to 1543X2 and 1533X2.

[Colin Alford]

I couldn’t find my “Factory Photos CD”, so I borrowed this album for the weekend.

While the 4 x factory photos of the 1533X2 have been shared numerous times, in the subsequent posts, I will provide a bunch of close-up images that may assist in ironing out some of the details of these vehicles.

[Colin Alford]

First 5 images

[Colin Alford]

Here are the next 5 close-ups

[Grant Bowker]

Following the discussion of how and where the outlet was mounted on MCP, I recently came across a through-frame outlet on a Chevrolet CMP frame that was being prepared for scrap. Don't cry, the frame really was beyond help. (heavily delaminated, shortened, non-standard wheelabse, bent, abused....)
The photos show where it was located on the CMP frame (between the left-hand step brackets) and the fitting. One end is shaped to take a standard 45 degree SAE (single) flare (see photo of mocked up 5/16" tube), the other is threaded similar to a schraeder tire valve stem. Although rusted, it looks to have been threaded both outside for a protective cap and inside to suit a valve core. I don't understand why they would have put a valve core here as any hose to inflate a tire would have had to incorporate a device to press the core open - otherwise the pressure from the pump would keep forcing the core closed so no air would flow. (and the core would restrict flow...)

[Grant Bowker]

More photos, inside of frame view and the fitting.
For those who are curious, the outside of the part that passes through the frame is threaded 1/2-20.
I believe the fitting is described as "connection assembly, tire pump frame" in the parts list which would make it part number 1799265 which doesn't have an asterisk* as a unique to CMP. But, I don't see that part number in the Chevrolet Master parts list 1929-1948....

[Grant Bowker]

More, to show the assembly to line...

[Lynn Eades]

Grant, I would suggest that is an inlet rather than an outlet?

[Grant Bowker]

I won't say you're wrong, but in the photo above (#218 from Colin) I'm convinced the inlet is the inverted triangle shape (or the air cleaner in the diagram) and the output is the hard (copper in the parts listing) line from the pump cylinder head heading toward the outside/left of the truck. Similar on both CMP and MCP that leads to either the through-frame fitting on a CMP or the running board fitting on MCP (see post #209). I don't see a reason to extend an inlet for the pump to the outside of the vehicle but you would certainly want the outlet for connection of a hose for tire inflation to be on the outside. MB-C2 supports the hard line being the outlet as does the structure of the ball check valve below the fitting for the hard line.

[Charlie Down]

Hi Grant and Lynn,

I must admit that I was under the impression that the triangular fitting, later replaced with the filter, was the inlet, and that the coiled copper tube connected to the frame, and outlet nozzle and airline. The opposite set up doesn't make sense to me, (but I've been wrong before)! However I don't think so this time.

[Hanno Spoelstra]

An incredible level of detail has come to light on this subject. Great to see how MLU members are collaborating in researching this vehicles!

I have attached two relevant pages from the AEDB Design Record, one of which was posted by Colin earlier.

It struck me that no maintenance manual is listed for the 1533X2, something I had not noted earlier. I would like to know if any of the other references listed have survived somewhere? They would be a goldmine for further info!

Design_Record_Volume_5_Basic_Bodies_and_Non-technical_Vehicles_0119.jpg Design_Record_Volume _4_Self_Propelled_Mechanical_Transport_Chassis_0061.jpg

[Tony Smith]

Interesting that the picture of the Pump shows the Ford version, fitted to a Ford gearbox!

[David Herbert]

I think that the second page (with the Ford tyre pump) is not directly related to any particular vehicle but a general comment on the need for a tyre pump and the problems of existing ones.

David

[Charlie Down]

I've been working on a specification for the Chevrolet 1533X2 MCP truck as built for the LRDG.
It was produced for an article in the second edition of the LRDG 'Tracks' magazine, which has just been published, edited by Kuno Gross, who is also a forum member. The article looks at the progressive modification made to the trucks over their operational history from March 1942 to the end of the campaign in mid 1943. It also looks at the tactical, supply and operational areas that contributed to the developments of the truck.
As a lot of the specification comes from this thread and forum, it seems appropriate to post my specification here, as a sort of thank you to everyone who has helped with the research. And to also get some feedback on its accuracy!

Chevrolet 1533X2 as it left the factory, as shown in attached photo.

• Flat face cowl (standard Chevrolet open cab) with wooden dash surround and with folding ‘Jeep’ style windscreen, fitted with windscreen wipers
• Extended width wings (80") with larger wheel cutouts
• 134 1/2” wheel base chassis with strengthening plates to achieve 2 ton classification
• Standard 216 ‘Stovebolt’ straight six engine without governor
• Heavy duty oil bath air cleaner
• Four speed gearbox
• Eaton two speed rear axle and speedometer adapter for different gear ranges
• Heavy duty Timkin front axle
• Auxiliary rear springs
• Double acting shock absorbers on both axles
• Engine driven air pump
• Heavy duty rear engine mounts
• 10.50-16 wheels and hubs
• 14” front and 16” rear brake drums
• Mud flaps at rear
• Heavy duty 3” deep radiator, and 6 bladed 18” shrouded fan
• Military front bumper (curved or angular) and radiator crash guard on raised mounts for greater ground clearance
• Military standard tow hitch,
• Under slung tool boxes attached to ammunition body
• Gotfredson 4B1 ammunition body
• Canvas cover for ammunition body
• POL 2 Gallon can racks on each side of the cab
• Canvas doors.
• Bench or 2x CMP style seats on fuel tank top plate.
• Headlight buckets without top fitted side lights
• Rubber bodied side lights fitted beside headlight on separate bracket.
  Rear light brackets fitted under ammo body with only side lights, no brake light or reflectors.
  Wireless suppression kit

The only production variations seem to be options of a bench seat or CMP seats, and curved or angular bumpers. I believe the bench seat was on initial builds, before being replaced by the more common CMP seats on a fuel tank top plate, but as to the background of the 2 types of bumper I have no idea which came first or was more common. The different types of bumper are hard to distinguish in most photographs.

The LRDG modified the trucks with various fitting on receiving them in Egypt, sand channel and mat mounts, condenser, compass, rear wooden stowage chest in 4B1 body, angled rear face of LHS wheel box to allow a spare wheel to be stowed between the box and tailgate, greedy boards, etc and then further modified them over the next year as a result of changing circumstances.

The point I'm not 100% sure of is whether there was a rear axle underside convoy light. I suspect there was, but can't confirm it. Also the type of steering box fitted. I have a part number 266794 with 3/8" filler plug, and replacement part when stock depleted 268325 with 1/2" filler plug (and 5266921 which just has a tag added), but not the details of the of what that looks like. (Colin Alford?)

Any feedback / information welcome.

1533x2.jpg