apply joint effort service call doesn't do much in gazebo

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Hi,

I have a ros node that connects to my gazebo model. It makes a service call to rotate the joints (wheels). If I perform the ros service call from the cmd line I am able to see the wheels move. However, from the cpp node, it doesn't seem to move. Here is my cpp code:

gazebo_msgs::ApplyJointEffort r; 
    r.request.duration = ros::Duration(2.);
    r.request.joint_name = "right_wheel_hinge";
ros::ServiceClient client2 = gazebo.serviceClient<gazebo_msgs::ApplyJointEffort>("/gazebo/apply_joint_effort"); client2.call(r);

I have this in my main function of my cpp file. I am starting with Gazebo, so your help is appreciated