Chevrolet 1533X2 30-cwt trucks

[Charlie Down]

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

[Charlie Down]

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!

[Charlie Down]

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?

[Grant Bowker]

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

[Charlie Down]

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!

[Colin Alford]

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

[Charlie Down]

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.