Inside tire wear on one axle may be an overloaded axle or an axle that no longer has the proper alignment. The axle should also have an arch up and if it doesn't have that it is either overloaded or was overloaded and is now damaged and needs to be replaced.
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You can get those differences due to more weight on one side than the other, or the pad you are on is not level.
That indicates a toe problem. Tires should be parallel to the frame and when measured as you did, the measurements should be equal.
A toe setting means the tires sit straight ahead toed in or toed out. It has nothing to do how flat the tire sits. That means if toe is off the tires would have a feathering or scuffing to them but that would effect the tires the same all the way across. Camber is how much the straight line down should trail behind. caster controls how the tire sits. Flat or on one edge or the other. That would be his problem. Being over weight loaded by a lot could contribute to the problem but more than likely he will need to get the alignment meaning bend the axles. Something else could be bent spindles That would also cause bad caster.
I have weighed the camper in the past but both axles on the same scales so not sure if I can weigh each axle separately? I have air bags under the bed frame to help with load, maybe adjust from 20 to 10 psi? Pin doesn't look nose high once hitched. And both axles have an arch. I have attached pics, hopefully be able to see clearly. Thanks for the tip on how to measure Rob!
No guarantee that the new axle will be right. The shop that does my alignments always does and alignment when replacing axles. Makes sense when you read about so many tire issues and the fact that Dexter usually replaces axles for free under warranty. They could easily deny replacement since it would be hard to prove the RV owner didn't hit anything.
Would be nice but true that, Thanks
I know about toe and camber and caster settings. Did front ends, suspension and alignments for most of my 25+ years as a professional mechanic. Improper toe will not wear the tires evenly across the tread due to the slight built in camber of trailer axles and the camber setting on vehicles. It will wear off either the inside or outside of the tire. Camber will not cause tire wear unless it is extreme. In that case it would be clearly visible.
