Tire pressure

FordTractorMan · Mar 20, 2011

Any recommendations on tire pressure for 18.4x38's - inner tires and duals? I think you generally run a little more air in the insides, right? Considering 20lbs inside & 18lbs in duals. Probly should mention I'm ripping ground. Thanks.

flying belgian · Mar 20, 2011

I always heard you should run half as much in duals as inside tires.

Fordfarmer · Mar 20, 2011

Rule of thumb I've heard and use is tire width (without the decimal) + 2 = pressure to use. 20 psi for an 18.4x38. Bias only, not radials. I have one set of duals that had a factory sticker on htem when I got them. Recommended 2/3 the pressure of the prime tire. This is for band type (clamp-on) duals, not axle mount. Would be 14 psi for 18.4's.

JMS/.MN · Mar 21, 2011

I"d go 16-18 max on the inside, 12-14 on the outside. Doesn"t matter the job. Would never run 20 lbs on main tires, duals or not. But yeah, more on the inside than what the duals are. I always figure, hitting field rocks with the outside tire, they need to give more when hitting them.....less stress on the axle. And if they puncture (never have in 38 years)..those worn ones are cheaper to replace.

Anonymous-0 · Mar 21, 2011

If they are radial tires as I do, I run 14 pounds in each and thats on a 2 wheel drive and 185 horse tractor if it is a pull type ripper. If it is a 3 point or mounted I would go with at least 18 pounds to keep the side walls from buckling, that is the main thing.

gene bender · Mar 21, 2011

What does your tire dealer say.

FordTractorMan · Mar 21, 2011

Haven't asked him. I always get good advice here.

oj · Mar 21, 2011

Big difference between bias or radials. If they are bias, then pressures of 15 - 18 psi are fine. If they are radials, they should be run a lot lower, we run our 18.4R42s at 8 psi single for field work, if they are dualled up we run around 6psi... they WILL pull better at lower pressures...

If you find out who is the rep for the tires you run in your area, they will be able to tell you the pressures to run based on tractor weight and loading. Our tire dealer told me to run 25psi in my radials, i told him he was stupid (after i gave him the cheque for the tires)and to give me the number of the tire rep, who told me 8 -10 psi...

hd6gtom · Mar 22, 2011

Bias ply tires 18 lbs inner and 14lbs in the duals. If you have radials post back with the star rating on the sidewalls.

Tire pressure

FordTractorMan

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flying belgian

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Fordfarmer

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JMS/.MN

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Anonymous-0

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gene bender

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FordTractorMan

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oj

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hd6gtom

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