M6 Bomb Service Truck information.

[Charlie Down]

I am researching details for the Chevrolet 1533X2 Long Range Desert Group truck. The particular area I'm trying to nail down is the riser panel on top of the fuel tank that allowed 2 CMP seats to be fitted instead of a bench seat. The only other Chevrolet truck I know off that had 2 seats on the fuel tank is the M6 Bomb Service truck.
I'm trying to get photos and dimensions of the M6 riser panels, of which there seems to be 2 types, one with raised rings pressed into it and the other with 'C's pressed in. Also the 'C' type seems to be much larger than the ring type. I can't find out why there are 2 different riser panels of different sizes, and therefore its not clear which one is appropriate for a Chevy 1533X2 truck built in 1941 in Canada.
The other information is from TM 9-765 parts catague which lists the following drawings, part numbers and figures which I would love to see.
M6 Panel cover, seat riser. Drawing and part number CV-471037 and fig 18-9.
Also M6 platform, with seat riser, assembly, drawing and part number CV-3666270 and fig 18-2.
These might help explain how it goes together or why there are 2 sizes/pattern, but maybe not!
I've attached some of my early research pages on the seating, factory photos showing the side view of the fuel tank frame and riser panel, and a LRDG truck showing a bit of detail of the side and rear of the fuel tank frame and riser.
Any help would be brilliant, I've been trying to work this all out for literally years and its the final detail I need.

[maple_leaf_eh]

I have no definitive information to bring to the conversation, however I've had two coffees this morning and am feeling a little brave.

I like your supposition that the individual seats could have been M6 Bomb truck parts. But .... notice the left side view at the link. The seat seems lower and the riser smooth-sided.
https://radionerds.com/index.php/Bom..._M6_(Chevrolet). There are other detailed photos in this 1942-dated manual https://radionerds.com/images/7/7e/T...E_TRUCK_M6.pdf

But, have you established (if it is possible) where and when your truck was manufactured, versus the M6 Bomb Truck's production history? You might be worrying about an impossibility. Yes Detroit is a small area, but the plants were flat out busy, and might not have cared to divert parts from their well-configured flow and process charts.

[Bruce Parker (RIP)]

Originally Posted by maple_leaf_eh

Yes Detroit is a small area, but the plants were flat out busy, and might not have cared to divert parts from their well-configured flow and process charts.

It may be my coffee speaking, but I'd suggest it would be easier for a plant to cobble together a quick drawing and die to stamp out a needed part than it would be to scour other production lines for something useable.

[Colin Alford]

Charlie,

After work today (approx 5 hours from now), I will post some images from the 1543X2 Parts list (unfortunately no diagrams) regarding seats. It appears that in 1941, all 1543X2 production switched from Bench seat to the DND (CMP Type) seats. Rifle racks were added at the same time. I think it is a safe bet that the same parts were used on the 1533X2.

I have not looked at the linked M6 Bomb truck manuals, but we may be able to compare part numbers between Canadian and US production.

Colin

[Charlie Down]

Thank you Terry, Bruce and Colin.
Agreed to all the above comments that I may be clutching at straws.
However there is no known other alternative at this time.
The 1533X2 was built in late 1941 and the M6 went into production a year later, so the 1533X2 riser was most likely adopted as a basic design for the M6. It may have been that the War Department wanted a simpler spare part chain and asked for the 2 x CMP seat option, or something similar, or GM/Chevrolet foresaw the possible need and devloped the riser after production of the 1533X2 started, so initial production trucks had benchs. It could be all sorts of reasons.
The same fuel tank/frame/bench seat was used throughout the war in production of the American GM G506 series of 1-1/2 trucks, so it wasn't that they ran out of bench seats. I think it likely that GM Canada products were shared on GM USA products, why make new designs when a design and machinery already exists.
That doesn't answer why there were 2 different sizes/patterns of M6 Riser panels though. And if there was a reason is it relevant to the 1533X2?
As Colin Alford states production from bench to CMP seats took place in 1941 for the 1543 trucks and most likely for the 1542 and 1533 trucks. So it could simply be production lines adopting more 'Military' fixtures on their MCP trucks as time/planning went on, or new parts became available.
Frustrating as this is creating lots of questions, but as yet no answers!
Looking forward to the photos Colin, however I may not answer for a while as its already gone 1.00 in the morning. I know thats a bit slack of me!

Still don't know what riser panel it was though!

[Colin Alford]

Charlie,

If you go to the radionerds.com site that Terry linked, and search for their M6 Bomb Service Truck page, then scroll to the bottom there are a number of links to manuals. At the bottom is part 2 of the Ord 9 Service Parts Catalogue. On page 74 you can find one of the illustrations ( including part numbers) that you are interesting in seeing.

Attached you should find images from the 1543X2 parts list showing the seats and rifle clips.

While I think that it is likely that the Canadian “Panel Assembly, seat riser cover” will be similar to the US version, I think there will probably be differences in the pressings.

You mentioned that it appears that there was an extra plate between the riser cover and seats. I also got this impression from the close-up images. However, looking at the parts list leads me to think that what we are seeing might be an angled vertical front edge on the “Angle, seat track”

Colin.

[Charlie Down]

Hi Colin,
I agree with you that the 'plate' between the riser and seat could well be the 'Angle seat track'. Its a bit of an optical illusiion. Once you start looking at it as a vertical , not horizontal plate, it makes more sense.
So now we have a part number for the seat riser panel -5809802 from GM/Chevrolet Canada for a 1543 and also part number CV-471037 for a M6 from US Ordnance service parts catalogue. What we now need are photos and dimensions of the parts for comparison.
One thing I have noticed is that there seems to be a smaller gap between the fuel tank frame and the edge of the cab floor compared to 1533X2 cabs. Does this indicate a smaller cab width on the M6 or larger fuel tank frame? Also attached a recently renovated M6 riser panel and fuel tank frame. Interesting to see how wide the flange is on the sides and the fixing bolt hole locations.