Controlling Hinge Direction to Drive

Hi!

I'm trying to create a cab and trailer that have their direction controlled by the angle of the joint/hinge (hitch)...like an articulating tractor. Has anyone done this before? I have the following script written, but my model in Unity doesn't react as expected. The log shows increases/decreases in Y value when the left/right arrow keys are pressed, and it moves forward/backward when the up/down arrows are pressed, but it won't turn on-screen. If you back up far enough, it eventually jackknifes (usually to the right, but sometimes to the left), but that's not exactly what I'm looking for. Has anyone had this problem? Any idea of a solution?

Thanks for any input you might have!


#pragmastrict
var speed:float=5; //speed of mobile
var turnSpeed: float=10; //turnspeed

functionStart () {
var trailerHinge = GetComponent(ConfigurableJoint);
trailerHinge.targetRotation = Quaternion.Euler(0,0,0);
}

functionUpdate () {
//grabtheinputaxis
var ourCurrentRotation: Vector3;
var steer=Input.GetAxis("Horizontal");
var gas=Input.GetAxis("Vertical");
var trailerHinge = GetComponent(ConfigurableJoint);
var turnAngle: Vector3;

var moveDist=gas*speed*Time.deltaTime;
var howMuchHasAngleChangedSinceWeLastChecked=steer*turnSpeed*Time.deltaTime;

ourCurrentRotation = trailerHinge.targetRotation.eulerAngles;

turnAngle = ourCurrentRotation + Vector3(0, howMuchHasAngleChangedSinceWeLastChecked,0);
trailerHinge.targetRotation = Quaternion.Euler(turnAngle);

//Quaternion.Euler(0,howMuchHasAngleChangedSinceWeLastChecked,0) + trailerHinge.targetRotation;

Debug.Log(trailerHinge.targetRotation.eulerAngles);

//andnowmoveforwardbymoveVect
transform.Translate(Vector3.forward*moveDist);
}