The GMC CCKW

Don in California e mailed me and pointed out that there is a difference in top vs bottom in mounting the gun ring over the cab.

The mounting tabs on the rings are definatly offset. We discussed which way is "correct"? Tall side up or Tall side down?

I was horrified to think my ring was mounted upside down! But close inspection and review of the illustrations in our trusty TM9-2016 manuals shows about half the rings on way and half the otherway.

I don't think the gun or gunner cares. Does anyone have more information on why the ring mounting lugs are offset and which way is correct?

Worried in Wisconsin

Cat Man

I don't know why there is an offset, unless it has to do with some clearance issue. But the factory installation manual that was packed inside Box 2 (M-36 mounts were shipped in two boxes) contains detailed installation instructions for both the M-36 (cast brackets) and the M-36 Optional, or Alternate (welded brackets). They specifically spell out the "tall" side of the M-49 ring goes up, and the bolts come in from the bottom with the nuts on top. It's not only shown that way, it actually spells out that this is the correct way to install it. If someone who knows how to post pictures wants to send me their e-mail addess, I can e-mail them the diagrams from the manual and perhaps they can be posted for everyone to see. DON

Pics of the manual provided by Don

Now that I think about it, since the distances between each of the M-49 ring welded-on mounting tabs is slightly different, it would make a difference if the ring was not mounted correctly. If it was upside-down, the brackets/poles would be in a slight bind. Probably wouldn't matter with a display gun, but a real .50 has a lot of recoil & it may be a problem if it's wrong. DON

Hello Don in CA,

Welcome to the CCKW site.

Outstanding technical information! Now that the entire HMV world knows the Cat Man has his CCKW ring mount on UP SIDE DOWN.

I'm forced deeper into the depths of winter depression and will have to seek medical attention or at least strong drink before I can get outside to remount the gun ring.

But that really is good information for everyone. We all learn more everyday. The installation manual is a really rare one. I've got a stack of CCKW manuals a foot tall but have never seen that one. Please PM me so we can talk about how to get a photo copy of that neat little manual.

Just for fun, how about the rest of our members? Any one else with a ring mount on upside down? Surely I'm not the only one?

Great information, Thanks again.

Cat Man

I'm surprized that you didn't have a "clearence "issue with the "trolley" hitting the bolts.
I know I did That was the clue I had done something wrong

John

Thanks, Cat Man. I didn't mean to publicly point out your ring was upside down (you took it public!), but I guess it will be interesting to see how many people did not realize those mounting tabs on M-49 rings are not evenly spaced around the outside. I used to be on this forum years ago, but I've been focused on other things lately and I finally checked back and found it better than ever. I couldn't remember my password or even which user name I used, so I just re-registered. Now that I can see the membership list, I noticed I was originally registered as Donald Jennings. Is there a way to combine them? One or the other can be eliminated if it matters. Bill Wolf said he would put those pages on pdf whatever that means, but hopefully that will allow people to see them in larger format so they're easier to read. The Ord 9 for the M-36 mount lists a different adapter plate number for the cast bracket M-36 vs. the welded bracket M-36 Alternate. I have only seen the flat steel adapter that seems to have originally been intended for the welded bracket. The Ord 9 drawing seems to show the cast bracket adapter had a ridge or thicker part on the outer edge of the plate. Are these common? Can someone describe the exact difference? DON

Welcome Back Don!

Hey Guys,
At the Evansville MVPA I was able to acquire a very complete M49 ring/M36 mount set(dated 1943) Thanks to this thread I'll be sure to mount the ring the correct side up!
My question is, what changes did you guys make concerning the mirror on the mount's side? The front leg will make displacement of the mirror mandatory. I did a forum search and a couple of years ago this was discussed but the pictures were no longer viewable (expired). Any recommendations out there? Thanks for any help!

I may be wrong, but I don't think these trucks had a right side mirror when the left the factory, so any mirror installed on the right side would be a field addition. This gives you a lot of flexability. The simplist mounting I've seen is just a "spacer" block with two holes drilled in it to mount the mirror base further forward enough so when the mirror arm sweeps back, it clears the gun mount leg. I suppose you could even get creative with this and offset the mirror base mounting on the spacer block toward the right, with seperate mounting bolts for mounting the spacer to the truck. This would be a little more complicated, but then the mirror base wouldn't need to stick out as far forward to clear the mount leg. There's probably even better ideas. DON

Hi Hammerhead,

Great to hear you got that Ring Mount at the MVPA convention.

On this Web site, you can go to the main menu and click on the tab for

"Technical Info" - Then Click "Gun Ring" - Then Click "M-36 Mount"and scroll down to the 18th photo. It is a close up of the right hand mirror spacer modification we did on our Dump Truck.

Other close ups of the ring mount as well. Hope that helps. Just be aware that I had the ring mounted upside down in these photo's (As Don pointed out) And I'm still going to therapy sessions for that error. Everything else should be correct.

Just don't hit your head when you stand up in the cab!

Cheers

Cat Man

Thanks Don and Catman!
I had actually gone to the "Gun Ring" section (which had 6 pictures) but hadn't clicked on the "M36 mount" tab thinking it was the same info. Duh! on my part. BTW Catman, that picture of the Trackson data plate appeared brand new. Does someone make replacement data plates? I've been trying to recondition mine but it was in pretty rough shape when I started. Mine is identical to that one except dated 1943.
Thanks again, Hammerhead

The data plate was found in a pile of stuff at an MVPA convention years ago. No idea where it came from. They make replacement plates for everything else. I suspect there is a reproduduction plate but have no clue how to find one.

Hey, be happy you got the "big" part!

Cat Man

I made my mirror spacer from two short pipe nipples I think 3" would do it and used longer bolts with washers under the bolt heads and washers and lock washers and nuts on the inside of the cab . Has worked just fine , may not be original but it is functional

Hammerhead wrote: Does someone make replacement data plates? I've been trying to recondition mine but it was in pretty rough shape when I started. Mine is identical to that one except dated 1943.
Thanks again, Hammerhead

Hello,
I make replacement data plates for military vehicles also for M36 ring , if you need.
regards
Robert
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