Passenger door lock broken

[psaboic]

Well, I think it is broken. Had the car locked, and when I went to use the key to open just the passenger side front door. the key turned, stuck for just a split second, then let go with a small pop. Trouble is, I think something broke as the door will now not lock or unlock with the key. It works just fine with the drivers door lock and will lock/unlock manually from inside the car. It just will not work with the key in the lock cylinder.

I suppose I am looking at taking the door panel off, but can anyone give me a head's up at what I am looking at fixing to get it working again?

On a different note, the car has also started to intermittantly have a harsh clunky type downshift from 3-2 and 2-1. More 2-1 but still a lot harsher than it used to be. Up shifts are fine. BTW, the car is (of course) the 83 300D

Glenn