Originally Posted by Lgbpop

OK, update.

Pierce put me onto the solution. Cheers, brother - and thanks. Popping the RF door panel clarified things.

For starters, the spring belonged in a location I hadn't expected...but, once I found where it lurked, I was able to install the replacement inside the LF door with some illuminatory help from the wife. (That's fancy talk for her holding a flashlight.)

Briefly....there is an extension of the inside-half latch housing which turns 90° toward the front of the door, following the doorskin. Attached to that is a bell crank, in turn attached to which is the inside vertical lock-linkage rod. That stupid little 84¢ spring I bought fits between the stationary extension and the bell crank. Once I figured out where it went, it was a somewhat simple matter of spreading the bell crank and bracket apart a bit; then I used a Dremel tool to put a small slot into the blade of a jeweler's screwdriver, to push the loose spring end into the bell-crank hole after I had it anchored into the extension. After that, I just bent the bell crank back into place close to the bracket/housing extension and replaced the linkage-rod clip.

No more slop in the LF lock-linkage rod. It's tight as a virgin now, excuse the expression.

BTW, this fix does NOT require removing the latch halves from the door skin!