only 1 of my 4 tires is worn off on the inside

When I bought our first TT used (99 Layton) I noticed uneven tire wear on the back two tires. Despite repacking the wheel bearings the problem persisted, so when it was time to get new tires, I repacked the wheel bearings, got the tires installed, and then made an appointment at a frame/alignment shop to have the axels looked at. They adjusted camber and the such and those new tires rode true and wore even until I sold it many years later.