My slider door was working perfectly until one day I parked on a hill. After using the slider to get something out of van it will no longer shut right. It's almost like some simple adjustment is off so door isn't hanging straight. I bought it used and don't have an owner's cd/dvd. Can anyone check and see if there is a simple adjustment to make the door hang straight again? ( the lower back edge of the slider door is out when door is closed, almost as if door is off kilter) I have appt to have it looked at but mechanic says NOTHING has been easy on that vehicle. Any tips I can share with him? Thank you