Aren't all 9.00 x 16 NDTs the Same ???

[w30bob]

Hi Guys,

Full disclosure........I don't know Jack Squat about military tires. But I thought all 9.00 x 16 NDTs had the same diameter, tread width, section width, etc. But apparently not. I recently bought 6 NDTs that had been mounted but not driven on. So I consider that pretty much brand new. I didn't notice it when I picked them up (because they were stacked on their sides), but when I stood them against the wall I thought I was seeing things. Look at the pics.

In the first pic, starting at the brick wall and moving right....the first 4 tires are all Denman 9.00x16. The 5th tire is a United 9.00x16. And the last tire is a Mohawk 9.00x16.
In the second pic (I rearranged them a bit for effect) the the first tire, going left to right, is the United, second the Mohawk, and the other 4 are the Denmans.
What's interesting besides the huge discrepency in diameter is the fact that the tread width of the Mohawk is wider than the other 5 and the tread width of the United is narrower than the other 5.

So what gives? I'm betting my truck would sure sit a bit funny with these guys mounted and installed. Help my sanity and tell me what's going on here?

regards,
bob






DSC04325 by w30bob, on Flickr


DSC04328 by w30bob, on Flickr

[DJ]

Same brand tires should be the same diameter, there can be a slight difference in brands though. The height difference will should be the same on like brands once the are mounted and properly inflated. A tire on the bottom of the pile will be squished flatter than one on the top,making it narrower and taller. Check the build dates on the 4 like brand tires,it's possible different molds were used if the dates are quite different.

[powerwagontim]

Hi Bob,
I may be wrong, but I bet if you mounted the 4 Denmans (Denmen pl?) and aired them up the differences would even out. Even if they didnt, I doubt you would notice once they were mounted. Thats why vehicles have a suspension system!
Tim

[w30bob]

Tim,

I hear ya, but the carcass construction for tires by the same manufacturer should be identical. I don't see how one or two of the Denmans can gain an inch or two in circumference when aired up while the other two do not. They'd have to come out of molds that differed by that much. I understand the differences between say a Denman and a United and a Mohawk. Ok, I don't understand why they would be different.....but if there's significant varibility I'd expect it to be between brands, not within the same brand and same tire line.

DJ,

I'm going to check the dates on them when I get back on Wednesday...........good point. With the military having MIL-SPECS for everything I just find it hard to believe they'd buy tires from a number of vendors that had different specifications. But I could be wrong. As for stacking them.....I'd offer up that the section width would be less the further down the pile you go, but the circumference shouldn't change unless the belts under the tread can stretch that much....and they wouldn't have to. What would "give" would be the beads on the tire. The tires at the bottom of pile would have their beads touching, which would shorten the section width.......so I don't know. I know I've stacked tires in my shed for years and never say anything near the variation I'm seeing here. It would be interesting if I could find specs for the Mohawk, United, and Denman 9.00x16 NDTs. I'll get my girlfriend right on that!

later guys,
bob

[Glenn]

I've got Denman's on my M37, and Firestone on my M43, and the Firestone tires are about an inch taller than the Denman. Tread width difference is not as noticeable. With all the different types of tires I've bought over the years I've always been amazed at the differences between manufacturers with the actual size versus advertised size, whether they are listed by section width or diameter.

Edit: after remeasuring it's really about one half inch height difference. Just a FWIW.

[pwrwagonfire]

We've got Mohawk NDT's on one of the Civi PW's at work...never seen them anywhere else till your picture!

[MSeriesRebuild]

If there is literally this much difference in height; your biggest concern is thrashing your differential spider/side gearing as the lower height tire will be making more revolutions that the taller one. This would be extremely detrimental to a differential.

As for anyone paying close attention to government mandated specs; that would be the joke of the week. They couldn't care less; manufacturer's and suppliers certainly know that, so if something didn't come out as advertised, well.

Diameters will certainly vary; you just need to make sure that what you run on the left and right of the same axle is the same diameter or you can expect gear issues. It is best if you run the same diameter on all 4 (or 6 wheels if a tandem arrangement). You can get by with slightly different diameters from front to rear, but it will matter on tire wear, and stress at the t/case when the front axle is locked in if the diameter is different on the front in respect to the rear. It's true, the military guys stuck whatever tire they had on and run them; but it doesn't mean they did not experience problems and eventual break downs as a result of doing it.

[Kaegi]

I have seen diameters range from 34 inches to over 36 inches with the average being around 36. many of these tires are not made for the gov. Power WAgons were built for decades for the civilian market and all the surplus WCs and M37s were also in need of tires in the real world so suppliers answered with their own designs. My next truck I will run the 10.50 x 16 if I can still get them. almost 38 inches tall gives more top end.

[ferroequinologist]

We've got Mohawk NDT's on one of the Civi PW's at work...never seen them anywhere else till your picture!

I'd never heard of them before, but my 'newest' m37 has the Mohawks, and they are different than the firestones on my B1 and the Goodyears on my buddies M37.

[MSeriesRebuild]

We've got Mohawk NDT's on one of the Civi PW's at work...never seen them anywhere else till your picture!

I'd never heard of them before, but my 'newest' m37 has the Mohawks, and they are different than the firestones on my B1 and the Goodyears on my buddies M37.

Mohawk was a common brand in the 60's. We used to run much larger sizes that brand in some heavy equipment applications.

[pwrwagonfire]

We've got Mohawk NDT's on one of the Civi PW's at work...never seen them anywhere else till your picture!

I'd never heard of them before, but my 'newest' m37 has the Mohawks, and they are different than the firestones on my B1 and the Goodyears on my buddies M37.

Mohawk was a common brand in the 60's. We used to run much larger sizes that brand in some heavy equipment applications.

Thanks!