Vehicle Wheels Sink through Floor (Collisions Ignored)

My vehicle wheels fall through the floor.
I tried:

  • Re-importing the FBX source asset, setting up the physics from scratch
  • Following different tutorials and reading up documentation
  • Contacting a Youtuber who used the same asset pack and followed his step-by-step

The wheels still sink through the floor, their collision is ignored completely in-game.
In the physics editor, it collides perfectly.
If I drop the car into my scene and simulate, it works fine and the collisions are correct - wheels even spin when the car moves.

The problem starts when:
I properly set up the wheels in the vehicle’s movement component (naming them, etc. in the correct order).

I’ve done everything accurately as every tutorial described, even the YouTuber who had used the same assets and got around the same problem and my issue persists.



Hey can you try increasing the uniform scale in your skeletal mesh and then reimporting the mesh using the reimport option on the top in the skeletal mesh editor. This helped me earlier when I faced the same issue. The Unfurom Scale value only seems to reflect when you reimport the mesh.

you need to apply roation and scale on the wheels and mesh

You might need to increase wheel radius in your Vehicle Wheel blueprint (or UVehicleWheel class)

increasing Wheel size (in BP/C++ class) will not work here, the minimal size is the Mesh’s size, not the Class’s setting.
i replied about it there:

This topic is about different thing, which i today learned how to fix (i posted my answer below).

If you have set everything correctly:

  1. measuring unit “cm”
  2. Joints dont have any rotations (they must be zeroed 0;0;0)
  3. Mesh is oriented as X to Forward (Y to side, Z to up)
  4. Z = up, not Y. Y = side.

then just read my post there:

Otherwise read that whole thread (just 2 pages, until my post).

I have solved exactly same issue, so i know what i link.


Setup your Vehicle in Blender like this

noticed the “no wheel collision” is avoidable by naming the Armature as Root instead of creating a dedicated Root Bone

Set Unit Scale to 0.01 units

Export with Armature and Mesh with transform settings as X = Forward, Z = Up and set Geometry as face

once on UE create a class from parent of VehicleWheeled as normal

do normal routine with PhysicsAsset and create blueprint wheel variants and the vehicle anim BP

your Vehicle Model “should not” fly away or sink if they are setup correctly

(if a YT tut is required reply to this asking for one and ill update with one)