Hi, I finished building my Wheelson and I followed the instructions to attach the wheels but they do not stay put. There was no click sound when fitting them in and there isn’t much space left on the white axle for them to not “spin out” once the wheels are in motion. As a result they fall off within seconds of the Wheelson igniting. I tried dismantling the car to verify the yellow engines, compare each side of the white axle, but nothing worked. I am thinking of putting a drop of crazy glue on each white axle so that it sticks to the red part of the wheel, but not sure that is a good idea… Please help me.
I Had same problem. Small amount of silicon fixed it. 
hey, thank you for supporting ou work.
Please place a tiny drop of glue on the wheels.