[coal miner]

Sounds to me like you could have what is called "Radial Pull" where the tire & casing is not made properly or is out of round. This ia a common problem on todays tires. If you take it to a tire shop or dealer that has a ROAD FORCE balancing machine they can tell you right away of
the tire is defective. This machine applies road force while the tire is being spun & balanced & any defect will show up. Also check the rim for any defect such as wobble or bent etc. This is best done by spinning it on a wheel balance machine without the tire & just by eye they can tell if the wheel is defective. Few tire shops spin just the wheel alone to check for any defect.
They just mount on a new tire & your done!
They have a name for this Road Force balancing machine but can't think of it at the moment. Also, you might want to check for proper air pressure in your tires & follow the owners manual specs or the tire chart on the door post of your truck. Most people & even tire shops put way to much pressure in your tires. I think my Tundra calls for 28 pounds in the front & 32 or 34 in the rear.

Lets hear how you make out & what the solution finally was? Coal miner in New Jersey - recently up from Florida.