Firestone says truck's perfectly aligned.

I'll give that a try.

Haven't won the Megamillions yet so...

 

Had same kind of issue and after taking truck to a few different alignment shops I found out it was my tires. I had just put new rims and tires on my truck when I had the issue and come to find out some of the new tires I bought had a broke cord inside causing my issue

 

If you ever figure it, let me know.
Mine has been getting progressively worse.
I’m too at the point of “not ever letting go of the steering wheel”

I’ve tried rotating the tires, wheel bearing (needed them, but it didn’t help the pull)
All suspension components look good, and it’s been aligned 5 times @ 3 different shops.

The only thing I haven’t tried is swapping different tires.

I got to get it figured out soon. I’m needing tires now.
I have almost 80k on these Hankooks. It’s pulled hard for the last 40k.
Tire ware is pretty much even, except for the last 15k, I didn’t rotate them.
The rear right tire has worn slightly more than the rest.
Which to my understanding is normal on an open diff that hasn’t had the tires rotated?

I’ll be the first to admit. I know little to nothing when it comes to alignment.

 

STT Maxx are symetrical there is not an indicator of outside or inside written on the sidewall of the tires. The thread pattern is the exact same.
Symetrical STT Maxx

Asymetrical Baja Boss

 

I agree that caster being that negative can cause some wandering and abnormal feel especially at highway speeds it is far too low!

 

Maybe you can call them symmetric and they certainly aren’t directional. But the tread is mirrored about a plane that is at an angle to the direction of rotation. The center section of tread is always angled the same way no matter how you flip the tire. So all four tires have a section of tread that is pointing to the right. This causes them to have a slight pull to the right.

 

Correct but still if the tire is causing the pull it is abnormal and should be addressed. If the company that put them on doesn't want to handle the claim it is a poor company to deal with. There are 100s of tires made that way and even with the maxx not all do it. My baja boss are much more aggressively like that and do not cause a pull. And no they aren't directional either. It's not symmetrical in the fact that you draw a line down the middle and you can fold in half and the exact mirror image is to the other side. But this is pretty much how all symmetrical tires are it's more on a 180* rotational axis than mirror image the STT Pro is the same way along with the 1000s of options of passenger car tires.

 

I think what you are having is right drift due to road crown. To tell, find a deserted two lane road and drive on the left lane and compare with the right lane. If it pulls to the left in the left lane your problem is the camber angles are the same. Have the alignment shop add +0.25 degrees left camber and see if it tracks straight.

 

I don’t believe in this ST Maxx pulling to the right conspiracy. I wore out a set of them and they never did that.

 

That's what it is a conspiracy. If people are getting pulls or drifts from them either they have a bad tire, alignment isn't set to account for road crown, 3 the tires are big enough to start "following" the wear in the road. It's common with big sidewall and larger sized tires to kinda drift around and follow the road and it's inconsistencies but usually those are 37+.

You can adjust for it with caster too just need about .5° difference between the 2 also the right camber they could adjust more neg or split the difference between camber cast and rt and left. It just takes an alignment tech that knows what he's doing

 

Tire pressure? Long shot

 

Another shop says they'll get to the bottom of it. If they have a competent mechanic I'm sure all it will take is money.

 

Yeah, That is the reason I’ve just “lived with it”.

I can’t find anything wrong.
I need to find some one with a different set of tires to try first.

I hate to admit I can’t see a thing wrong.
Neither have 3 different shops. When I figure it out. I’ll let you know.

 

OP did you ever get this resolved?

 

I’d not figure it out.
New tires and it still pulls right.
Not near as bad, but it will eventually get just as bad as the tires wear.

I guess I’ll just rotate them often.
I’m starting to think there maybe a bent spindle? I have no idea what it is.

 

Although caster is out of spec, adding more caster to both sides to bring it into spec, will NOT correct a pulling problem. Nor, will as previously stated, adding more positive caster to the left side - that will make the pull worse. Caster pull is toward the negative side.
I've seen steering racks cause a pull - it does happen. As previously mentioned, Jack the front end up & start the car - if the wheel turns, even slightly twitches toward the right, you've found your problem. I used to be a technician & I'd just test drive the car & shut off the engine while driving to get the same diagnosis. I wouldn't advise doing this unless you are a competent driver who knows what happens when you have no power steering and how to handle it. Safety first!
The alignment specs shown should should be fine as far as a pull is concerned. I usually gave 2-3 tenths more right caster to compensate for road crown. Slightly negative caster might cause wandering but not a pull.
Either tires (including pressure), a worn suspension or the steering rack is causing the pull. I've even seen an out-of-phase steering shaft cause a pull, but still can't wrap my head around that one! Good luck. Let us know what you find

 

I won't ever take any of my vehicles to a firestone.

 

As the saying goes,
"Play stupid games, win stupid prizes"