I can't tell 100% from your photo, but I think you're aiming for the wrong servo. Depending on whether or not you have dual zone, there are 3 or 4 servos in the system. I *think* you're pointing to the passenger side "air mix damper servo", which controls the vent air temperature by balancing the mix of heated and cool air. In a dual zone system, there's also an air mix servo in the same position on the driver's side. The air mix servo(s) typically fail first since they get the most usage as the computer constantly adjusts the balance of hot/cool air to maintain cabin temp. The failure mode is a clicking noise as the computer tries to adjust the air balance, but can no longer read the position of the door except at the hot/cold extremes of travel.
Vent selection is controlled by the upper center servo, referred to as the "air outlet damper servo" in the shop manual. This would seem to be your failure point if you can select one or more desired outlets. Grinding sounds like it might be jammed or gummed up.
The last servo controls recirc\fresh air and is labeled "air inlet damper control".