Tire Size Difference

[TenTires]

Hi, Im not familiar on how these tire sizes work. I just bought my deuce last week and I was told today that my front and back tires might be different sizes and cause problems within the drivetrain in 6WD. I have the Michelin X's on the front and 11-20's on the rear. I think the X's said 14.5-20(?) on the sidewall. What does this translate to in terms of standard (size in inches) size, are my front and rear tires different sizes, and is this going to cause a problem in 6WD?

 

[Westech]

I think the 14.5xl and the 11:00 is the same size and should not be a problem.

 

[TenTires]

Where can I find a size converter?

 

[Westech]

http://www.alfaheaven.com/MilitarySection/Accessories/Tires.html

 

[papercu]

Different sizes on the same axle is the main problem. I've heard that you are suppose to measure the circumference of each tire and match them together and even an inflation mismatch greater than 5 psi means that the two tires in a dual assembly are significantly different in circumference and will cause problems. http://www.ryderfleetproducts.com/cgi-bin/ryderfp/technicalbulletins/tireair.jsp Wayne

 

[TenTires]

Thanks Westech! So, based on this chart, the fronts are 44", the rears are 43". How much difference in RPM will that make in between the front and rear when in 6WD? Enough to cause binding or other problems?



Tire, 14.5R2044" tall - 12.5" treadwidth, 4 ply

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Tire, 1100x2043" tall - 9" treadwidth, 12 ply

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[Alex400]

Have you measured the overall height of the tires on your truck? I ask because the tires when they were measured probably were measured on different rims than what you have on the deuce. I would be out a tape measure and get a good measurement with weight on the tires.

 

[ida34]

I know of a truck with 11 XLs on the back for clearance and 14 XLs on front without causing a problem. You could always just measure around the middle of both tires to make sure they are close.

 

[gringeltaube]

Tire size

Thanks Westech! So, based on this chart, the fronts are 44", the rears are 43". How much difference in RPM will that make in between the front and rear when in 6WD? Enough to cause binding or other problems?

Tire, 14.5R2044" tall - 12.5" treadwidth, 4 ply

Tire, 1100x2043" tall - 9" treadwidth, 12 ply

NOT from a tire catalog but measured myself!: Michelin 14.5R20 XLs are 43" new. Static rolling radius only is 20.5" (on front axle, MF, @45psi).
11.00-20 mil NDT are more or less 42.5" depending on manufacturer. Rolling radius (MF, frt. axle, @60psi) is very similar to 14.5s due to relatively less sidewall flexing being non-radials.
11.00R20 XLs are same O.D. and radius as 14.5s.

No problem at all operating in 6WD!


Take a look at attached chart showing actual diameters of most common sizes between 40 and 50 inches.


And just keep in mind that 14.5s require 11" wide MPT type rims (M35A3)!

G.

 

[TenTires]

Hmm. Great info! You say that I HAVE to run the MPT type rims? Why is that exactly? (not that I disagree with you or anything, I bought the truck with the tires and rims on it so I dont know)

 

[M1075]

Hmm. Great info! You say that I HAVE to run the MPT type rims? Why is that exactly? (not that I disagree with you or anything, I bought the truck with the tires and rims on it so I dont know)

There are different bead (flange?) heights. G has covered this before in detail with a diagram. I always enjoy reading his posts, because he knows more about military tires/wheels than anyone I know.

The M35A3 wheels are MPT, but could also be used with standard tires (15.5/80R20 for example). Unfortunately, you can't go the other way.

 

[TenTires]

Yeah, but if you look at the pic that I posted in the beginning of the thread, I already AM running them on the stock tires. The truck came this way...So, why do I HAVE to get a different rim if its ALREADY working on the original ones?

 

[DanMartin]

Follow the link in this post: http://www.steelsoldiers.com/showpost.php?p=302586&postcount=29

 

[emr]

use em they are fine, if it were a street truck screaming down dry roads may be a different story in all wheel drive, but i seriously thought u will ever go screaming down a dry road in all wheel mode and doing multiple turns...in the conditions u will use it it will never make a difference never...its way close enough....Randy

 

[TenTires]

Yeah, thats what I figured. Thanks!