Suspension problem - Leaning airbags on drive axle. Please advise where is the problem

The spring are together 2 on each side you don't replace one I can see the spring has shifted. Look at the other side does the spring look the same. If you also notice the bolt on the bracket has play in where the leaf springs sit on.

 

Aside from a broken u- bolt. Which isn’t the case. The centering pin on the spring or maybe the spacer/ block is probably rusted out or sheared off.Causing it to shift. If so you’ll need to replace damaged parts, Springs and or blocks, unless you can get an experienced welder to weld a new centering pin. “ (tit) “ on the spring(s) , it can be done. Welding and grinding it to fit. Might as well replace bushings while your at it, they look worn to Me. New U bolts also, old ones can’t be reused as they’re designed to stretch when torqued. If re used they won’t stay tight.

 

Then do as @Socal Xpress suggested and take it to a shop. A reputable shop.

 

All 4 zsprings and a leaf springs on top should match as far as part numbers, and those part numbers are stamped on front side of both. This picture has zspring part number 20476781

 

Previous post I made a mistake it’s a leaf spring part number cause it’s on the bottom but here’s how it looks on a 2013 truck, the numbers on a top are the part number.

 

Here you can see all the parts. Do you have this plastic square in place??? It’s minimum thickness 15mm and maximum 27mm.

 

There was a OP on here a couple months ago, had a Volvo with the wrong blocks on his springs. The torsion bar would hit the frame at times. They all figured out it was a problem on certain year Volvo, Somehow his Truck had wrong size blocks, Might want to dig in and check part numbers or compare suspensions on other Volvo’s side by side. Has to be a cause, bad parts or something. His looked like axle was twisting, about same as yours

 

I’m thinking the centering pins have to be gone.They line up with holes in spring between U Bolts

 

Best advice !!!