Unstable driving down the road

I'm with you but it can definitely be tires too.

 

Not doubting that a bit (The factory setting), I’m questioning the statement it “needs some pull towards each other to keep it tight.”

 

For what it’s worth, I did alignments on cars for 5 years. I agree it sounds like alignment issue. I know if the toe is off it will make one drive “squirrelly” also the castor being off can too. Every vehicle has positive castor from the factory to help it drive better. Unfortunately most truck alignment shops set the toe and send the truck down the road. If you take it to an alignment shop, it needs to be a good one that understands your problem and what you are trying to correct.

 

*And those are REALLY hard to find. I live in a pretty good sized city. Trucks everywhere. ONE known truck alignment shop and I've asked around for years. I just don't see how this happens but so far it's the way it is.

 

Too high tire pressure on the rear tandems. Try to keep them at only 100psi.

 

Same happens to me. Yesterday i replaced 8 drive tires Douublecoin and now when i switch lane the truck is acting weird, it’s kinda goes left and right and then straight up weird feeling.