Car not slide by gravity

Good day!

I have problem with my wheelcollider car.
Car not slide by gravity with new Unity5. In Unity4 this cod work great.

if(CurrentSpeed == 0)//We ready to roll
{
foreach (WheelCollider col in WColBack)
{
col.motorTorque = 0.0f;//reset
col.brakeTorque = 0f;//reset
}
foreach (WheelCollider col in WColForward)
{
col.motorTorque = 0.0f;//reset
col.brakeTorque = 0f;//reset
}
}

But now car stay in place and not roll by gravity
Anyone pleace help!

Best Regard, Nick

 

Decide this problem. Read car unity example.
Thanks