Bent Axle or Wheel Hub?

Well I don't know what you are measuring but I would assume so where they can come up with as much as four inches difference is if both right wheels were located at their minimum spacing and both left wheels happen to be at there max distance. Each wheel can be an inch plus or minus from exact. The most I ever saw was just under three inches, but as you can tell four inches was possible. Like I said the first time it was pointed out to me I was certain the car had been in a major collision. I also had a group of Ford trucks (F350) that was eating front tires and our front end man showed me the movement in the rubber bushings. They appeared to be worn out so took back to dealer and was told they were all in spec so no repair. we cut the rivets, replaced all the rubber bushing with after market ones then tire wear went away. The next ones we bought didn't have the soft bushings. If you deal with enough vehicles sooner or later I think you will see almost everything. Ford also had a transmission problem with some Taurus models, They replaced the transmission in one of ours and the pan was marked do not remove no service required. We ran the car it's full life cycle with no service and no problems.

No I'm talking about measuring rear axle center to front spindle center with front wheels exactly straight.
on vehicles with independent suspension some specs allow any given wheel to be off as much as an inch forward or backward. This can cause a max difference of four inches but hardly ever does. But back in the 80s an inch or two was somewhat common. A car with a solid rear axle will never be that far off or it would track off to one side or doglegged as we used to call it.

Ok but this is getting way off track on the trailer site.