DevonGarver, I really hate to drag up this old thread but did you ever find a solution?
I have the exact same issue. Even down to letting go of the wheel in sweeping left hand turns and staying perfectly in my lane.
In truth I hadn't thought of the steering stabilizer and will start there but have been through everything else and 3 different alignment shops.(in 6k miles)
And yes the problem started the day I installed my Nitto Trail Grapplers. Go figure?
All the shops blamed road crown, but the roads here (mostly divided hwy 2 lanes each direction) are crowned to center so it should pull right in the right lane left in the left lane. It pulls hard left in the left lane and goes almost straight in the right, but still a little left.
I eventually quit trying to fix it and just drove it but my tires are wearing unevenly now and I can tell the constant pressure on the steering gear is wearing it out prematurely as well. It's loosened up a lot in the last year, all in the steering gearbox. The rest of the suspension is tight.
So effectively another BTTP.

 

UGH. I'm sorry to hear you are experiencing the same thing. Short answer is NO-I have not solved my problem. I have improved things drastically, but if I go into a sweeping left turn I can still let go of the wheel and keep turning left, just as bad as before. I put a dual steering stabilizer on it from PMF. It helped some, but certainly did not eliminate the issue. I began playing with tire pressures, and found that running the fronts at about 61-62 psi and rears about 60 psi while empty yielded the best amount of control up front. Any higher pressure up front and it would float really bad and want to pull harder to the left. As for the tire wear, I have been rotating every 5k miles and it has been keeping them wearing pretty even. I never did try to pull the ball joints apart as recommended by Tom on here, but I checked them while installed and both sides felt the same. I feel like there is something out of alignment with the whole front axle, that is not apparent on the alignment rack. It seems like the aggressive tires just exaggerate the issue and we never noticed it before with only factory tires. I have decided to just deal with it, and when this truck is paid off in two years...I may or may not replace it with a new one. I really hope you have better luck resolving your issue than mine...but it sounds like you exhausted your options just like me, with the exception of the stabilizer. Let me know if you figure anything out, or have any questions about the stabilizer.

 

Thanks for the response. I just got back to this thread. Well apparently I need to try some different tires to be sure. Perhaps one of my super duty friends will let me swap them on for a test drive. I'll do this and report back. Might be a week or so. I'm swamped right now.