I started to do a valve adjustment today and got the valve cover off and everything ready to go, but I don't have a barring tool. So, I tried to use the alternator nut to turn the crank, but the nut loosened. Is there any other way? Can I rent a barring tool? It looks like an oversized torx bit, does anyone know what size it is? How can I make sure my alternator nut is tight?