I hate to burst your bubble, there's not supposed the be a spring. What's an axle and hook? It's called a starter bendex. I'm not sure if they're available or not. It should be. Can you leave the starter out an push start the 40, and see if the noise is gone? Evidently your parked on an...
Get a stethoscope or put a long screwdriver to your ear and start touching stuff while it's rattling. Get a length of hose, like heater hose, one end to the ear and move the other end around to isolate the location.