Hi,
Thanks for your help. I discovered that when I imported my .fbx file, if I went to the physics asset, ue4 didn’t already created separate collisions shapes for the wheels as it didn’t seem to recognize that the wheels where connected to them.
Anyway, I watched the tutorial mentionned in the post you send me (Blender to UE4 Vehicle Workflow - Unreal Engine 4 Tutorial - YouTube) and I applied rotation and scale on the armature from Blender and carefully placed the origin of the armature to the origin of the root bone.
Now it’s working fine, thanks for the help!