Unlocking the Driver's door with the key is not easy,
the lock is rather stiff and reluctant (sluggish ?) to turn once you get it to the point that it is actually
moving things inside the door. More than once I've been a
wee bit worried that I might break the key off in it.
The car has electric locks, which work fine once you're
in it. Any quick clues would be appreciated...

Remove  the door panel and spray all moving parts with PB Breaker (or your equivalent). WD40 is another name brand here in the US.

After you get done and it dries, White Lithium Grease  will help keep it lubed.  If you'r afraid to use Grease near the key lock mechanism, try a graphite lubricant.

I had the same problem. It's just age and oxidation. My passenger side door isn't 100% yet. I'll fix it this weekend though.

I would actually remove the door lock from the door and clean it out with a brake cleaner or some laquer thinner.  After that I would lubricate if door lock lubricate/graphite.  do not use WD 40 or any type of grease.  Certain lubricates will and can absorb moisture from the air.  This moisture can cause more corrosion and possibly freeze in cold weather.  Plus you don't want wd40 or grease always winding up in your pocket or running down the inside of the door or outside of the door when it gets hot.

 

 

 

 

 Good point...I hadn't thought about that. Guess I'll clean the grease out and go with graphite. 

ive got the same problems on my 79, ill try that too.

Yo thanks for all that guys. I musta forgot to "tick" the
little box that sez email me wen someon replies, 'cos I
didn't realise until I checked the forum tonite that there had been some ! Duuhhhhhh. Oh well live and learn. I have now added TLC to doors to the growing list of luv my vette winter jobbies. (Yes, we are heading into winter here.) Have been side tracked presently playing with fitting new bulbs to instrument cluster. GM must employ human pretzels to do this - I turned myself inside out just the once and then went straight to the pull it apart option. Much easier on the body !!!

Update...

Finally got to it on my list, bit the bullet, pulled
the door panel off, and removed the wee hatch at the
bottom. Have now determined that the lock & barrel and
linkages are all nice and free, but the electric actuator is "heavy" and "sluggish" to move by hand. If I disconnect the rod from the key/barrel to the electric
actuator, all is dandy. The actuator actually works ok electrically. However being able to unlock the drivers
door without fear of breaking the key off is where I
want to be at, so I am about to embark on a "remove and
refurbish the electric actuator" adventure. If anyone
else has been here done this, would love to hear from you !

Cheers, Chris D.

Quick question (if anyone is still watching this) - when you turn the key in the door lock, apart from locking/unlocking the door should this also be physically pushing/pulling the power actator arm in and out ?

Or has a previous owner messed up the linkages inside the door on me ?

It occurred to me that I would have thought the power actuator rod would be in some sort of a slotted link, so that when turning the key the linkage would ride up and down the slot (easy) instead of trying to physically drag the power actuator arm in and out as well (which seriously increases key turning effort !)

Anyone know ?

Chris

 

 

 

They have been constructed by GM both ways.  If it's slotted, so be it.  If not many often do move the actuator.  It depends on the design of the actuator.

Update... I bit the bullet, and pulled the linkages and
electric actuator out. Not as dramatic an experience as
I had anticipated. (It's always a bit of worry when you
play with bits you can only feel but not see, as in this
case where it is buried behind the door panel.)

Any way the good news is that it is now better. Unlocking with the key is still "sluggish" as the actuator is unavoidably moved as well, but at least it is no longer threatening to break the key off.

Once I had it all out, I clened all the rod pivot points
and lubed them. I also popped the electric motor off
the actuator and cleaned the two ends of the spindle.
No lube for this though, as they run in nylon bushes so
lube is a no no here. However if the spindles have accumulated crud on the ends (as they do after 20 odd
years) then the motor doesn't rotate totally freely, and
this means extra drag when the rods push and pull the
actuator when using the key. Watch out if you do this
though, as there are a pair of wee brushes about the
diameter of a matchstick and 3/16 inch long which will
happily fall out of place when you pull off the electric
motor. A bit of a balancing act with tweezers to put
them back !

Anyway it is better as a result, so I am happy. If
anyone wants details let me know - there are a few
handy tricks I learned along the way during this exercise.