Yes, everyone's truck is that different. With things like tire wear and drift it's all of the little things that add up to create the "perfect storm" so to speak. Second, Caster Angle ABSOLUTELY has a DRASTIC effect on whether the vehicle will pull left or right. If you adjust your left caster 1.5 degrees less positive than your right caster, it will induce a left pull, and vice versa. I appreciate your desire to not "let fundamental misinformation stand", but please do not be the cause of the misinformation in the process. Lastly, I recieved a response from Toyo about the tires. I was correct, they are known for having a pull to the right. But notice how they state it is not every single truck? This is as I said above, caused by the fact that everyone's truck is setup slightly different, and when you have the right combination of things occuring this issue presents itself more drastically, than others. Here is the response:

Thank you for contacting Toyo Tires USA. There is a phenomenon on some single axle applications that may cause a right pull due to the tread pattern and aggressiveness of the tire itself. This does not occur on every application, however it has been known to occur. If you have this issue and your dealer can not resolve it, it is recommended to return within the Trial Offer period if you chose to remove the tires.

If you need anything further please let us know.

Sincerely,
Consumer Relations
Toyo Tires U.S.A. Corp.
5665 Plaza Drive Suite 300
Cypress, CA 90630
800-442-8696

 

Now wait a minute...

"On some single axle applications". Because the dissimilar tread patterns don't always track in the same direction. I thought your had 4 of the same Cooper tires?

 

Ummm, Caster, camber, or toe can ALL cause a pull to one side or the other.

 

If you were right, then a grocery cart should be pulling all over the place with a caster angle if zero. And please tell me how you're going to adjust caster 1.5 degrees off from left to right on a solid axle. I didn't intend for people to try to make up weird scenarios where they can imagine effects.

 

I used to think the same. But caster is adjusted not by shimming the axle, but with caster bushings that fit around the balljoints. This way you can alter the angle of the knuckle against the rest of the axle to adjust caster.

 

lol yes I have 4 of the same coopers, what they mean by single axle is monobeam, as in solid axle, not independant front suspension. I sent them all of my truck information in the email so they knew exactly what I was asking about. When you submit an email it requires you to fill out a form with what tire you are asking about, what vehicle it is on, etc.

 

Respectfully, I think you are altering the meaning of what they're saying so as to make it support your argument. They say "Single" axle...NOT solid axle. It's commonplace to refer to the front or rear set of wheels on a single axle. Look at the door sticker on any passenger car and you'll see the "Gross Axle Weight Rating" acronym.

A single axle tire application is installing tires on the front or rear of a vehicle. Technically wouldn't yours be a double axle application with a solid front and rear axle?

 

A grocery cart does not have a caster angle of zero.....read post #27 here. I am not trying to be mean, but Here is a good page with information that still applies to street vehicles for you to brush up on in case you have forgotten some of the basics. As for the adjustment of caster angle, as Tom said, we use bushings in the knuckle where the stud of the ball joint goes. They are a cam design so you can rotate them and it changes the position of the stud which enables the adjustment of the caster angle. They also make ones that are preset at specific degrees, such as 1.0, 1.5, 2.0 etc.

 

That is an interesting idea, I do not think that is what is meant, as you wouldn't replace just two tires at a time...but I will email them back to clarify.

 

OK I emailed them back. I am curious though, what do you propose they DID mean then? A trailer with a single axle? Or if I were to only install two tires on the truck? For what it is worth, my exact question was this:

I have a simple, specific question. Does the Toyo Open Country M/T tire have any history of causing a slight radial pull to the right when installed on a neutrally aligned solid axle truck like my F250?

This is after I filled out the require form with all of my vehicle information.

 

It makes sense that tires mounted on only one axle may track a little bit differently than the tread of the tires on the other axle. If the tread were the same and they tracked a little bit to one side the off-tracking would be symmetrical and you'd not notice a pull as the truck would move down the roads just a little bit crooked. Of course if one axle tracks differently than the other axle a pull may be evident because the disparity between the two of them would cause the truck to rotate requiring countersteering to stay straight. This would present itself to the driver as a pull.

But if the tires are identical they should track the same. Meaning any off-tracking would be symmetrical between the front and rear axles and they wouldn't cause a pull.

 

Easy ....just cut the axle on that given side, rotate it to the caster needed and re-weld.
Still his issues could be caused by the lift/oversize tires.

 

So I removed the stabilizer today. It fully extended in about 3 seconds after I took the stud out of the drag link. I took it for a ride and let the tires warm up fully and it definitely does not pull as bad. It still pulls left, but takes much longer to do so. The only thing it still does that truly concerns me happens when I go around a left hand curve in the road. If I let go of the wheel in the middle of the curve it stays where it is, instead of straightening out and shooting me into the ditch like it should. It does not do this on a right hand curve. I crawled back under the truck and checked the drag link ends and the tie rod ends. All are tight. The tie rod ends rotate a little more freely than I remember, but they have zero lateral play. The track bar bushing and ball joint felt solid. No play at all. I am wondering if I jack the truck up and turn the ignition on if I will see the wheels turn slightly left....maybe I will try that next.

EDIT: I went out and jacked up the front end. Turned on the key and nothing happened. The steering wheel just sat there mocking me, saying "you dummy, of course I'm not going to move on my own". I did however have my wife crank the wheel over back and forth while I looked for issues. I found nothing out of the ordinary. At this point, I am still unsure of the cause. However, I did order a dual stabilizer kit today from PMF.

 

OK I received a response back from Toyo after asking for clarification on the meaning of "single axle". It was rather short but here is what they said:

"Being a phenomenon it has occurred on different applications, but solid axle’s seem to be the ones that we have heard about."

That seems pretty clear to me.

I love how we have devoted more time to talking about tires that I don't even own than we have talking about my problem with the truck lol.
But that's quite alright as I think we all are here to learn, and I just learned something, so that's good by me.

 

Now this is interesting. The last time I heard of this happen to anyone was when they installed new balljoints. One of the joints was far too stiff which caused the wheel to not return when turning in one direction. Based on that I'd say you should check those out.

Do you have a tie rod or pitman arm puller? If so, disconnect each tie rod from the steering knuckle with the truck in the air and see how hard they are to move. Each knuckle should be movable with your hands...if one is much tighter than the other you've found your problem.