My 1996 dodge caravan was fine until i felt my steering wheel very hard i try turning and it was very hard to turn. I parked and checked power steering fluid and it was empty . I noticed that the belt fell off completely i installed the belt back on everything is fine but now when i put the car to drive or reverse i hear a weird noise like is something is hitting .... when i put it in park theres no noise ... what can it be ? please help