The GMC CCKW

Is more than many want to have in their CCKW . I have some old Military 750X20 NDT skins here that will give a little relief to those looking to save 70%. You come, I'll load. Might make them rear ends on those Bantam Crane trucks work a little easier.

I have found that 'old skins' thend to do one of two things: get cry rot cracks or in the case of some older CCKW tires I have obtained get hard and weare easily.

But you use 'em anyway. Right?

I wish I was closer I would buy some, but too far to drive .

The stork is not available this week.

Rats, just my luck.

Are these just tires, tubes and flaps or do they have wheels?

>But you use 'em anyway. Right?

I try not to If I can. Those older tires also tend to be larger in diameter than the new Denmans I have been equiping my HMVs with. I will pair an old tire with a new one on the rear because the cargo CCKW never carries anything like what Annie the crane has for weight.

These are good take offs, no wheels no flaps, I do not use Denmans as they are stingy with the rubber and made their 750X20 NDT Tires smaller than anyone else. (I'd swear they use a 700X20 mold) I now use New STA Tires which compare to the other good brands. The WWII USofA NDTs all vary some between brands, but none are as small as the cheap Denmans.
Annie needs 750X20 tires so as not to tax the differentials. The STAs are nearly identical to the 70s dated US Govt Surplus 750X20 UNIROYALS I mounted on my CCJKW. I used to sell new Denmans and dumped the 10 new ones I put on my CCKW as they just looked too small, and were.

I take these in trade on new 750X20s, I sent 9 or 10 40s-50s dated onesup to the inlaws farm a couple years ago and they are on farm equipment and holding up well. I just took in another 7 or 8 last month.

I have used Denmans for years for a number of reasons:

- They are always available
- They seem to wear well
- My spedo is within 2 mph at 35 when measured by the police
- A matched set is no problem
- I can buy more years later and get the exact same size
- I do not have to rely upon 40's or 50's rubber that has been exposed to ozone and or sunlight for all those years. You would't put tires with those charastics on your family car...

And even if they were smaller, it would be easier on the CCKW power train by your own statement (Re Annie with 9.00 x 20's)

Denman 750X20s are approx 3/4" less diameter than STA, and original later GI 50s-70s dated UNIROYALS. Also, DENMANS are 3/4"Less than 40s-50s dated US Royals, Firestones, BF Goodrich, Pennsylvanias. I can spot a CCKW with Denmans from quite a distance, as they have that roller skate wheel look. The Army used 750X20s into the 70s at least, as there were a number of modified WWII trailer chassis, and platforms for electronics still in use. I bought the last of the US made GI Surplus UNIROYALS in the 90s. I will buy all NOS I can find. I have a small collection of WWII and 50s dated 600X16 NDTs as well, and am always looking for 40s-50s dated NOS Jeep tires.

Wow, i never knew that tires , no matter what they had cast on them, were different in sizes from manufacturer to manufacturer. Is this only in the 7:50 x 20 tires or does this go for all tires, regardless of size?

There is some variation between manufacturers (just talking 40s-50s Military tires), the TMs on the 6X6 Trucks and WWII Tire TMs explain this and show how to match your tires. The 750X20 Denmans are really gross when it comes to nominal diameters or heights of their tires. It is apparant they have skimped in material somewhere. I have seen a lot of CCKWs with GI tires, having grown up in the business since the 40s, Denmans are not the same as the original issue tires. As far as Ozone resistance, they did not get the Mil Spec treatment when I sold them. FYI, the 600X16 NDTs made today do not have the same BL(Bead Lock) spec for Combat wheels as WWII, it is not a requirement. Except for having Nylon Cord, todays repro tires probably will not take the punishment WWII GI spec tires did.
Joel

Thanks for the info.

50,000+ miles, most of them with Denmans on my cargo CCKW with zero, nada, nyet problems. I will stick with them as opposed to what I can 'find and match' out there

Rear tire diameter match
Changing the oil
Greasing the truck

are the 3 most important things you can do for a CCKW

Everyone out there has to decide for themselves

We had customers that could haul 7 cords of logs on CCKWs using WWII Tires, a Denman would blow under those loads. I had farmers with M-Series 2 1/2 Tons hauling grain that blew new 900X20 Denmans and I went back to selling new GI Issue 900X20 tires that did not blow. I would not put a Denman on a wheelbarrow.

Your experience is different than mine:

I have carried either the M151A2 or the GPW in the back for 1000's of miles (not all at one time) without a problem. Not a terrible lot of weight, but no problems either! Annie will be a better test someday...

I will keep buying Denmans Other owners have to decide for themselves

can any one tell me about the size of the specialty tires of america 7.50-20s or the new firestone repro 7.50 -20s?