Vehicle physics problem (again !)

Hey, I have tried for 2 weeks to make a custom vehicle in UE4. Everything was going good but at the moment I lauched the game, wheels hasn’t had collisions. When I inspected my model with “pxvis collision”, I saw that wheels’s collision “box” were snaped to my root bone and no to my wheels bones and I don’t know why. I think I’m going crazy because of that.

(I’m sorry for my English, it’s not my native language)