I know that Unity 5 Wheel Colliders are much good than old Wheel Colliders, but much more unstable than old Wheel Colliders too.
If your main rigidbody size is not equal to 1, 1, 1, your wheel colliders will be placed at wrong places.
If your vehicle’s collider is mesh collider, your wheel colliders will be crooked sometimes.
Unity’s documentation about wheel colliders are outdated (Still).
Wheels will slip at the beginning of applying torque (Sometimes).
WheelColliders get stucked when vehicle speed is 0. Just apply angular force by AddRelativeTorque to the vehicle while speed at 0 (Sometimes).
Default wheel collider settings are fine, but you have to be careful about mass value. E.g. if your vehicle mass is 1500, then your wheelcolliders mass must be at 100 - 150. Otherwise, wheel will bornout and will reach over rpms.
Is there a any detailed information about new wheel colliders?
Thanks