MLU FORUM  

Go Back   MLU FORUM > MILITARY VEHICLES > The Softskin Forum

Notices

Reply
 
Thread Tools Display Modes
  #1  
Old 11-12-20, 00:06
Charlie Down Charlie Down is offline
Registered User
 
Join Date: Aug 2020
Location: Bristol, UK
Posts: 140
Default C30 Chassis

I'm trying to find out if the Chevrolet C30 chassis frame was the same as the 134" MCP chassis, as used on the 1533X2 LRDG truck. Any ideas? If there were any differences, what were they?
Many thanks
Reply With Quote
  #2  
Old 11-12-20, 00:26
Hanno Spoelstra's Avatar
Hanno Spoelstra Hanno Spoelstra is offline
MLU Administrator
 
Join Date: Feb 2003
Location: The Netherlands
Posts: 14,400
Default

Quote:
Originally Posted by Charlie Down View Post
I'm trying to find out if the Chevrolet C30 chassis frame was the same as the 134" MCP chassis, as used on the 1533X2 LRDG truck. Any ideas? If there were any differences, what were they?
Many thanks
I don't think so, but please check wanted: Chev CMP chassis views for reference info on the C30/C60S chassis.
Reply With Quote
  #3  
Old 11-12-20, 01:58
Grant Bowker Grant Bowker is offline
Registered User
 
Join Date: Jul 2006
Location: Ottawa, Canada
Posts: 2,285
Default

My first guess would be "no" with the C30 being 4x4 and the LRDG 4x2.


I don't have a 1533x2 parts list to compare to the C30/C60s but by parallel and looking at 1542x2 and C60L parts books (both LWB), all frame rails and crossmembers have different part numbers from the corresponding part on the other truck. The differences may not have been great but there was something different to cause a different part number.
Reply With Quote
  #4  
Old 11-12-20, 12:06
David Herbert David Herbert is offline
Registered User
 
Join Date: Mar 2010
Location: Ayrshire, Scotland - previously Suffolk
Posts: 547
Default

In general (not particularly in answer to this question) different part numbers can mean just a couple of extra holes in an identical pressing or even an identical part from a different supplier. Or a totally different part.

David
Reply With Quote
  #5  
Old 11-12-20, 12:29
Hanno Spoelstra's Avatar
Hanno Spoelstra Hanno Spoelstra is offline
MLU Administrator
 
Join Date: Feb 2003
Location: The Netherlands
Posts: 14,400
Default 1543x2

Quote:
Originally Posted by Grant Bowker View Post
My first guess would be "no" with the C30 being 4x4 and the LRDG 4x2.
Agree. Look at the C8 4x4 and C15 4x2 chassis, they differ a lot.

Quote:
I don't have a 1533x2 parts list to compare to the C30/C60s but by parallel and looking at 1542x2 and C60L parts books (both LWB), all frame rails and crossmembers have different part numbers from the corresponding part on the other truck. The differences may not have been great but there was something different to cause a different part number.
I presume you mean the 1543X2?

Charlie, that would be my starting point for modeling purposes. As far as I can tell the 1543X2 was the LWB version of the 1533X2.

Reply With Quote
  #6  
Old 12-12-20, 03:21
Grant Bowker Grant Bowker is offline
Registered User
 
Join Date: Jul 2006
Location: Ottawa, Canada
Posts: 2,285
Default

My apologies, it is the 1542X1 and 1542X3 parts lists I was looking at.
Attached Thumbnails
CC60LX3-01 front.jpg  
Reply With Quote
  #7  
Old 12-12-20, 10:10
Hanno Spoelstra's Avatar
Hanno Spoelstra Hanno Spoelstra is offline
MLU Administrator
 
Join Date: Feb 2003
Location: The Netherlands
Posts: 14,400
Default

Quote:
Originally Posted by Grant Bowker View Post
My apologies, it is the 1542X1 and 1542X3 parts lists I was looking at.
Thanks Grant. What was the difference between a 1542 and 1543? Not familiar with the coding system.

I do know X1,X2,X3 etc are export destination codes - see http://www.mapleleafup.net/forums/sh...694#post147694

Edit - from the revised link I learned:
Quote:
1542x3 3-ton 160" w.b.
1533x2 3-ton 134 1/2" w.b. with 9.00 x 16 wheels
1543x2 3-ton 160" w.b. with dual performance axle and 20x6 wheels and single rears
So the 1542 was a regular 3-ton 160" w.b. truck, while the 1543 was the same but with the Eaton 2-speed axle? If that what "dual performance axle" stands for, that is.

Last edited by Hanno Spoelstra; 12-12-20 at 14:46. Reason: Edited to add info
Reply With Quote
  #8  
Old 12-12-20, 11:58
Mike Kelly's Avatar
Mike Kelly Mike Kelly is offline
Fan of Lord Nuffield
 
Join Date: Feb 2003
Location: Victoria Australia
Posts: 5,607
Default chassis

Quote:
Originally Posted by Hanno Spoelstra View Post
Agree. Look at the C8 4x4 and C15 4x2 chassis, they differ a lot.
Not sure where this discussion is going but the C8A 4X4 chassis and the C8 4X2 chassis are virtually identical except for the middle crossmember , I've had both types and they clearly used the 4X2 chassis as the basis for the C8A
__________________
1940 cab 11 C8
1940 Morris-Commercial PU
1941 Morris-Commercial CS8
1940 Chev. 15cwt GS Van ( Aust.)
1942-45 Jeep salad
Reply With Quote
  #9  
Old 12-12-20, 14:42
Hanno Spoelstra's Avatar
Hanno Spoelstra Hanno Spoelstra is offline
MLU Administrator
 
Join Date: Feb 2003
Location: The Netherlands
Posts: 14,400
Default

Quote:
Originally Posted by Mike Kelly View Post
Not sure where this discussion is going but the C8A 4X4 chassis and the C8 4X2 chassis are virtually identical except for the middle crossmember , I've had both types and they clearly used the 4X2 chassis as the basis for the C8A
Maybe you are right. From my recollection when seeing them side-by-side there was quite some difference.

Anyway: do you know "if the Chevrolet C30 chassis frame was the same as the 134" MCP chassis, as used on the 1533X2 LRDG truck"?
Reply With Quote
  #10  
Old 12-12-20, 21:21
Charlie Down Charlie Down is offline
Registered User
 
Join Date: Aug 2020
Location: Bristol, UK
Posts: 140
Default

This is going down an interesting route.

I am intrigued that the 1542 and 1543 differences were a 'dual performance axle', which I assume is a 2-speed axle. Does that mean that the last '3' of 1533X2 also means a 2-speed axle and a '1532' truck would have a conventional axle? Would clear up some differences of opinion in the LRDG interest groups. I have been looking for evidence of this other than fuzzy photos for some time. The LRDG specification for the truck does not mention the 2-speed axle, which is a stumbling block for some to be convinced of the 2-speed fixing despite photos.

My original post was to determine whether it would be practical to use an IBG model C30A chassis (I know there are issues with the cab, but its not needed for my build, and the suspension components are a generation better than Tamiya parts.) to do an accurate 1533X2, rather than 'bodge' the 1972 Tamiya kit. Having done lots of research on the LRDG 1533X2 I can't not use it to build the model! Any build needs good and accurate foundations hence the chassis. Looking at numerous posts, On-line parts catalogues, and GM Heritage site for information I think my best bet is to do a scratch built chassis and cross kit various components. The C30A chassis, although related, is not the same as the 1533X2 chassis, but that was a conclusion based on your collective help, so thank you everyone.
Reply With Quote
  #11  
Old 13-12-20, 17:27
Charlie Down Charlie Down is offline
Registered User
 
Join Date: Aug 2020
Location: Bristol, UK
Posts: 140
Default

I have found drawings of both types of chassis from Maple Leaf up Forum and from the GM Heritage Centre website. I have grouped them together for comparison. The CMP chassis is a generic view and needs to be 33"s longer I think, between frames 3 and 4 to become a 134" chassis, but its the clearest view for comparisons sake. The most obvious difference is the angles at the front of the chassis with the MCP chassis having a more downward pointing end to the frame. This, I presume, is to accommodate the I beam axle for 2 wheel drive as opposed to the driven front axle on the C30 CMP chassis. There are other differences such as strengthening gussets on various cross members of the CMP chassis, as well as the lack of strengthening plates on the mid section of the CMP chassis. Despite my research I haven't found the width of the CMP chassis (more likely didn't notice it when looking for other details). I know the MCP chassis was 25-7/16" at the front and 36 at the rear and had a wheel base of 134-1/2". The MCP chassis diagram isn't great but ok for comparison. Ideally a better diagram would be helpful. I have attached another drawing to show the MCP strengthening plates on the mid section of the chassis. Hope that helps.
Attached Thumbnails
Chassis comparison.jpg   MCP Chassis.jpg   Chassi side plate.jpg  
Reply With Quote
  #12  
Old 14-12-20, 00:39
Grant Bowker Grant Bowker is offline
Registered User
 
Join Date: Jul 2006
Location: Ottawa, Canada
Posts: 2,285
Default

By coincidence we were walking around the CMPs in the field today and the width of the frame (outside of rails) is 34".
Reply With Quote
  #13  
Old 14-12-20, 01:03
Charlie Down Charlie Down is offline
Registered User
 
Join Date: Aug 2020
Location: Bristol, UK
Posts: 140
Default

I got some measurements for a chevy Blitz chassis courtesy of Allan Mazlin, from MCP Vehicles Australia. I've added the measurements to my comparison slide of the MCP chassis for clarity. The MCP Chassis is wider at the back and narrower at the front compared to the CMP chassis. I would have thought the CMP would be wider for military use to make it stronger and more stable. Surprising result. Also the spring hangers seem to be arranged differently. According to the GM Heritage site the MCP rear springs with auxiliary leaves were 46" or 1168mm long and 2-1/2" 63mm wide. It would be interesting to compare blitz rear springs to see if they have been modified (lengthened or shortened) with the rest of the CMP Chassis. I believe the MCP chassis had extensions to fit the Military front bumpers on, which made the chassis even longer.
Attached Thumbnails
MCP-CMP.jpg  
Reply With Quote
  #14  
Old 14-12-20, 01:49
Hanno Spoelstra's Avatar
Hanno Spoelstra Hanno Spoelstra is offline
MLU Administrator
 
Join Date: Feb 2003
Location: The Netherlands
Posts: 14,400
Default

Good work Charlie.

See http://www.mapleleafup.net/vehicles/.../chevspec.html for spring specs
Reply With Quote
  #15  
Old 14-12-20, 02:16
Grant Bowker Grant Bowker is offline
Registered User
 
Join Date: Jul 2006
Location: Ottawa, Canada
Posts: 2,285
Default

I'm not sure when it started (one source gives 1938) but I'm fairly certain that the 34" outside width of frame rails is a SAE standard, established to permit interchange of bodies between chassis of different manufacturers (to save body makers from having to make different bodies for Ford, Chevrolet, Dodge, etc.). In the same vein, the distances from back of cab to rear axle are also very close to standardized - for the same reason.
One reason that the lighter modern pickup trucks still have wider frames is that they are pretty much designed to have proprietary bodywork and single rear wheels rather than specialist manufacturer bodies and dual rear wheels.
Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
For Sale: For sale C15 Chassis and HUW C8A chassis Alex van de Wetering For Sale Or Wanted 9 05-07-21 23:29
CMP chassis for what? Ilian Filipov The Softskin Forum 15 27-11-19 04:32
Cab 12 on a 13 chassis? DaveBuckle The Softskin Forum 3 07-02-19 10:23
Chassis winch in 15-cwt chassis Hanno Spoelstra The Softskin Forum 15 05-10-17 01:44
Ford M-H LP3A 1941 chassis = CMP Ford chassis cliff The Softskin Forum 5 11-07-14 07:22


All times are GMT +2. The time now is 09:51.


Powered by vBulletin® Version 3.8.4
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright © Maple Leaf Up, 2003-2016