Door lock repair?

[bc3j]

Can a door lock be repaired? My driver's side door will not lock. When I look through the top of the door with the window down I can see the inside of the lock.  When turning the key, the end of the lock cylinder with the link rod does not move in proportion to the movement of the key. I can move the key the full range between lock and unlock but the end with the link rod moves very little. I can see the center of the lock moving in relationship to the key but link rod moves very little.  The link rod is connected between the door latch and the lock cylinder.

Is there a nut on the disc that holds the link rod at the end of the lock cylinder that would make the key and rod not move together?  Or is the lock cylinder bad?  The door opens normally with both the exterior and interior handles just can't lock the door. The inside lock rod between the arm rest and the door latch is not connected.  Is that part of the problem?

What do you guys think?

[jimynick]

If memory serves, the link that comes off the door cylinder is shaped to fit the end of the barrel coming out of the cylinder and it may have worn out or the retaining clip may have done a burton. It's meant to move in the same ratio as the barrel, so something's not kosher. Take it out and see. 

[bc3j]

Thanks. Didn't know how the back was assembled.

[Racer57]

The entire locking mechanism is very simple and a locksmith can easily make new keys.

[Giveitawack]

There are NOS kits on ebay with cylinders for both doors + ignition. Then you have the same key for the doors and ignition.

[larry4406]

On my 71 and 72 cudas the door and ignition are same key with pentastar shaped end. The round head key works the trunk, glove box, and console.