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.

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.

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.

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.

First 5 images

Here are the next 5 close-ups

Here are the last 5 close-ups from the 1533X2 photos.

Here are 2 x close-ups from the 1543X2 section of the album showing the configuration of the left side of the transmission showing the tire pump (note lack of vertical control rod as would be fitted to a CMP), and speedometer adaptor (showing the connection to the rear axle shifter).

I have also included an illustration from CC60L-HB1 of the same area to assist in identifying parts.

Wow, Colin - just wow!

That's is brilliant. Thank you so much Colin.

LRDG Chevrolet 1533X2 fuel tank cover for dual seats
 

From my research most LRDG 1533X2 trucks had the twin CMP seat arrangement. This required a riser plate on the fuel tank to give the CMP seats a horizontal surface to bolt onto. The original fuel tank protector strip slopes down towards the rear to accommodate the bench seat which were the standard fit on pre war Chevrolet trucks. It would make sense to use an existing riser panel for this, instead of making one specifically for just 200 trucks. I've been trying to find the cover plate and think I may have found it, or at least got considerably closer. The attached photos show close ups of the seats mounted on a factory fresh 1533X2 provided by Colin Alford on the main LRDG 1533x2 page. The last photos shows fuel tank cover plates from 2 different 1942 M6 Chevrolet Bomb Service trucks. I believe (hope) that they are the same plate on the M6 and the 1533X2, although on the 1533X2 it looks like they trimmed the edges back, which gave more room for the Lee Enfield rifles to be stowed beside the seats and it doesn't have the 4 protruding bolt housings on the front edge, using just nuts and bolts to secure the panel to the fuel tank protector. In the 1533X2 photos you can see an additional plate attached between the seats and fuel tank riser panel.
I've since found that production of the M6 Bomb Service truck started in late 1942, so the 1533X2 had the seat riser before the M6 existed. That means that GM/Chevrolet designed one for the 1533X2 and then used it on the M6, or they anticipated the need for a riser panel on a series of potential trucks and it was then available for the 1533X2 once the bench seats ran out.
Any comments/ additional information or corrections welcome!

PTO Compressor filter
 

The PTO Compressor seems to have various air intake options. In the attached montage you can see illustrations of cylindrical and 'Kidney' shaped filters as well as simple inverted 'V' shaped inlets. Has anyone got any photos of the filters or have any knowledge which arrangment would be used in 1942 in North Africa?

Some of the filter/intakes look a lot like engine valve cover vents used on later Chevrolets if you need to make one up...

Hi Grant,
Thanks for the info. I've been searching the old postings and have narrowed it down to a fitted filter on Chevrolet compressors and the inverted 'v' inlet on Ford compressors.

http://www.mapleleafup.net/forums/sh...ght=compressor

I think the attached photo of a transmission breather for CMP could be a close relative of the part, but it would be nice to have something a bit more definite!

Charlie,

The Chevrolet tire pumps started with the ‘inverted v’ air intakes, then transitioned to the air cleaner. The 1543X2 parts list indicates that the air cleaner was fitted to “after jobs”, but there is no indication of an exact serial number.

Attached are 4 images. The first two are from the 1543X2 parts list (as discussed before, Chevrolet used many “standard” illustrations in their parts manuals and while this shows the Control rod which is actuated through the floor of a CMP, I am quite positive that this is incorrect for the 1543X2 and 1533X2). The third and fourth images are from the CMP Parts lists C8A-04, and C30-03, to illustrate that the tire pump air cleaner is the same as the transfer case air cleaner. On both the C8A, and C30 the transfer case air cleaner was added in 1942, but i do not know if this would have coincided with air cleaners being added to the tire pump.

Colin

Thanks Colin for clearing that up.
From what you say the 1533X2's would most likely have had the inverted 'V' inlet as they were produced in 1941. Later production vehicles would have had the filter if they had been ordered (the LRDG wanted to order another 200 trucks in late 1942 but by then it was clear operations in North Africa were winding down, so no authourity was given), with the filter being the same part as the Transfer case air cleaner. Trucks could possibly have been upgraded with filter system, but LRDG documents don't mention any other factory upgrades being retrofitted and it seems unlikely for such a small order in faraway Egypt that it was thought about. Now someone will prove me wrong!
So the attached photo would be the most likely set up (with push/pull rod controls) for the LRDG 1533X2 as delivered.

Tire Pump outlet (frame mounted on CMP)
 

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...)

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....

More, to show the assembly to line...

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

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.

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.

AEDB Design Record
 

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!

Attachment 125787 Attachment 125788

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

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

LRDG 1533X2 Specification
 

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.

Attachment 127913

PTO compressor
 

Here's a factory photo of the tyre pump on a 1533X2 Chevrolet. It's the same as used on the CMPs.

Hi Keith,
Nice quality photo, however the controls for the pump on the 1533X2 were different. The 1533X2 controls came out the side of the cab on the passenger side door sill next to the airline connector, as opposed to the screw driver being used through a hole in the cab floor. See photo on reply no 209, page 7 of this post.

Do you have any other factory photos you can share?
We have nearly covered every detail of the 1533X2 on this post and always looking for more information/photos to complete the picture or confirm theories.

1533x2
 

I realised when I checked it was the GMEXL7, not sure which of the MCP configurations that was.
These are the other photos I have, they have been enlarged by a factor of 4X from quite small images.

Charging switch panel
 

I've been looking at tracking down details of the charging panel on the Wireless trucks, and found some photos of Chevrolet WAs with a panel on the outside of the rear body. On the basis that the LRDG re-used items throughout their Desert campaign on different trucks, Aero screens and Wireless set ups for example, then the charging switch panel would most likely be re-used too. I was sent some documents by Bob Amos-Jones that were very useful too.
To summarise what I found out I'll cover the whole wireless setup. The LRDG used a WS11 High Power unit with Windom centre feed or sometimes end feed aerials on 16' duraluminium poles stowed on the trucks, and the 4' rod aerials for local (100 mile range) communication between Patrols. The power supply was fed through a 'Special' series/parallel switch for trickle charging/wireless use, from 2 standard 6 Volt batteries, one the truck battery, the other a 'booster' battery to provide the necessary 12 volts with the truck battery for the wireless. The 'booster' was mounted on the side step in front of the driver. During long periods of stationary Patrol, Road Watch, the Patrol would either take a chore horse to recharge the batteries or swap batteries with the other trucks in the Patrol. Very high levels of training were given to the signallers, this being the primary reason for the successful long range communication, not the limitations of the wireless. Very high levels of maintenance were given to the wireless and accessories throughout the Patrol too. No information is given on what periods of the campaign chore horses are used, but it seems they were more common later on. I suspect that all the Chevrolet 1533X2 trucks, and most likely the CMP Ford F30s were fitted with wireless suppression fittings as standard, but on the WA's not so sure. Most likely the ones from the Egyptian Army would be suppressed, which would therefore be primary choice for wireless trucks, but not the ones sourced from the civilian dealership in Alexandria.

I've put a drawing together of the series/parallel switch based on the photos attached (not dimensionally accurate and most likely wrong with some details, but its something to work on!), and on the assumption its the same switch, but on the Chevrolet WA's it had a protective edge due to its external mounting on the outside of the rear body, but on the Chevrolet 1533X2 no protection was needed because it was mounted in the cab behind the Drivers seat. No photos found yet of its location on the Ford F30's, but its not externally mounted on the rear body, or in the cab, based on the limited number of photos showing those area of wireless trucks. It may be mounted in the plywood wireless compartment, or possibly in one of the tool boxes below the wireless compartment. Hopefully something will turn up.