Importing cars from maya

I am experiencing a little problem importing cars into Unity from Maya. After i add the car script from "VehicleExample" the wheels are not rotating in the normal direction, instead they revolve to right or left. I've added an empty cube and added the car body and wheels as child and rotated them in supposed direction and now instead of rolling they tumble along an axis. This happened with almost all cars imported from Maya and i can't figure out what is wrong. If someone else encountered this please help me.



Thanks,

Mastereve