How to use

com.jme3.bullet.joints.SliderJoint

constructor

rb2.setPhysicsLocation(new Vector3f(4f, 0f, 0f));
SliderJoint joint = new SliderJoint(rb1, rb2,
    new Vector3f(2f, 0f, 0f),
    new Vector3f(-2f, 0f, 0f), true);

slider=new SliderJoint(driver, vehicle, Vector3f.UNIT_Y.negate(), Vector3f.UNIT_Y, true);
slider.setUpperLinLimit(.1f);
slider.setLowerLinLimit(-.1f);