is the fan supposed to spin freely when vehicle is off.?....could this be related to rattling sound in front end when engine is under a load?

 

Yes, this is a clutch fan. It will spin freely with the engine off.

 

no it should not spin "freely"

it should spin a little bit with the engine off if you push onit, but mine(same as when i got it) spins less than 1/4 turn by hand with the engine off idk if its related to your rattling but if the clutch is going and y ou drive in hot climates than you could have an overheating problem