Since you can move the steering rod a little bit, I'd disconnect it from the cable and start working it to see if you can get it to move freely again. Since it's spinning, I'm leaning towards the steering cable being frozen. Once you have the steering cable disconnected, at the motor end, try turning the wheel. If it's smooth, no need to replace. If it's jerky or stuck, then I'd just replace it. When putting it all back together, make sure you put the wheel at the center of travel (i.e. count the number of turns from stop to stop and then turn it back half of that) and have the motor centered up. Good luck!