Weird problem, trailer sway and possible 5th wheel issue?

That tire looks like it was rubbing on something. In anycase probably would not cause the drifting trailer. Looks like some one has dragged the trailer over a few curbs getting into deliverys.

 

What are the biggest reasons they do that?

 

Sharp metal edge.

 

Man, I hope not...

 

Check the fifth wheel plate that it has grease/lube. If it’s dry, you could get what you’re explaining.

 

Oh, this isn't about pretzel rods again, is it,,but I agree^^^, a dry 5th wheel does all kinds of things, but seems to me, the tire wear is indicating a severe alignment issue. Loose wheel bearings may be more noticeable under load, tire pressure maybe?

 

Those are the Michelin XDA 5+ tires, not retreads. And when they’re new they have 30/32 tread which would absolutely make the truck feel like the back end is sliding out from under you. It will probably feel this way for a couple weeks at least. And the reason the tread looks the way it does is because they used a truing machine on them.

Edit: I also see your tires are 11r22.5. Tall sidewalls with nearly an inch of tread on new tires will make the back end feel loose.

 

It's my truck it took 4 hours of time. Plus getting to mechanic and having them order 5th wheel ect....

 

Adjust your mirrors and see if that helps.