My grandfather ran 18 wheeler logging trucks for 50 years and nothing takes a beating like these, and never once did he ever take one for an alignment like what was said. I ran the maintence shop in a very large cabinet shop for 10 years, and never once did we send one of our 18 wheelers for this kind of alignment and we had some driver run them off in the worst of places on construction sites.
A bearing check will cost $0.00. I'd be willing to bet you had loose or bad bearings, OR your over weight and don't realize it.
Is your nose of the rig way high or way low? You need to be pulling level.