How to clamp rotation of wheels along longitudinal axis ?

My wheels are wobbling, but I thought may be clamping rotation along longitudinal (Z) axis would help.


I used this code taken from WheelColliderTutorial:

Code (CSharp):

1. using UnityEngine;
2. using System.Collections;
3. using System.Collections.Generic;
4.  
5. [System.Serializable]
6. public class AxleInfo {
7.     public WheelCollider leftWheel;
8.     public WheelCollider rightWheel;
9.     public bool motor;
10.     public bool steering;
11. }
12.  
13. public class CarController : MonoBehaviour {
14.     public List<AxleInfo> axleInfos;
15.     public float maxMotorTorque;
16.     public float maxSteeringAngle;
17.  
18.     // finds the corresponding visual wheel
19.     // correctly applies the transform
20.     public void ApplyLocalPositionToVisuals(WheelCollider collider)
21.     {
22.         if (collider.transform.childCount == 0) {
23.         return;
24.         }
25.  
26.         Transform visualWheel = collider.transform.GetChild(0);
27.  
28.         Vector3 position;
29.         Quaternion rotation;
30.         collider.GetWorldPose(out position, out rotation);
31.  
32.         visualWheel.transform.position = position;
33.         visualWheel.transform.rotation = rotation;
34.     }
35.  
36.     public void FixedUpdate()
37.     {
38.         float motor = maxMotorTorque * Input.GetAxis("Vertical");
39.         float steering = maxSteeringAngle * Input.GetAxis("Horizontal");
40.  
41.         foreach (AxleInfo axleInfo in axleInfos) {
42.         if (axleInfo.steering) {
43.             axleInfo.leftWheel.steerAngle = steering;
44.             axleInfo.rightWheel.steerAngle = steering;
45.         }
46.         if (axleInfo.motor) {
47.             axleInfo.leftWheel.motorTorque = motor;
48.             axleInfo.rightWheel.motorTorque = motor;
49.         }
50.         ApplyLocalPositionToVisuals(axleInfo.leftWheel);
51.         ApplyLocalPositionToVisuals(axleInfo.rightWheel);
52.         }
53.     }
54. }

(I have empty object with WheelCollider, it has child - visualWheel with mesh.
I think visualWheel should be clamped, because it seems only mesh is wobbling but not parent object with WheelCollider.
More details about this problem: https://forum.unity3d.com/threads/wobbling-wheels.472638/)