On my murray tractor I disabled the automatic driving so I could push it. Just like the diagram says. But when I try to push it, the tires in the back spin in opposite directions! If the left goes clockwise, the right goes counter-clockwise! Is this normal? If the engine is running will it drive straight?

Its fine the rear and is what you would call limited slip when one tire gets stuick the other one will turn and help get u unstuck