Recently I discovered an issue with my driver's side door lock. I almost never use it, because I usualy do not have the targa top on, and so thier is no point on locking the door - anyone can just reach in over the window and pull up on the door locking knob.
Anyway, while repairing the slow window issue on the passenger side (required restringing the entire window) I decided to lubricate the lock, and so when I replaced the door edge lamp on the driver's side I figured I should do the same. At this point I noticed that the driver's side lock does not return to center when turning the key - this means that you have to fiddle with the key to get the lock to stay down, and be able to remove the key.
Anyway, I decided that this would drive me nuts, so I removed the door card (yet again!) and then unbolted the door lock (below picture of passenger side, forgot to take driver side photo)
When I removed the lock I found the issue. There is a return spring that wraps around the lock assembly, and the ends of the spring stick through the shell into the plug. When the plug is rotated from center, either one side or the other of the return spring gets engadged, trying to pull it back to center. One arm of the return sptring had sheared off, right at the bend.
To repair it I first cleaned off all the old, accumulated grease with brake cleaner and then slid the return spring out of the slot and off the end of the barrel. I then bent a new arm (of about 5.5mm) in the spring right where it had sheared. I then slid it back over the barell, and engadged each end of the spring. Beacuse the spring is very slightly shorter (around 10mm) it is probably very slightly harder to turn, but this is not in any way noticialbe (and the spring has probably lost some of it's tension over time, so this cancels out :-))
I then sprayed the keyway with dry lube, and the whole body with spray lithium. A small bit of RTV silocone goes on the head / barrel nut to try keep it all waterproof, and done!
Some photos of the repaired lock: