[Dave from England]

Attending a show in September last year I parked up got out of the car & closed the drivers door.Long story short when it came to leave for home I could not open the drivers door & neither could five other car owners that tried.Climbed in through the passenger side & drove home.After putting the car away I called on my body man to open the door which he couldn't.It proved a real pain in the backside to get the door panel off not being able to open the door.With the door panel off he eventually opened the door.The latch was checked to see if it was functioning as it should and it was.Fastend the latch back in place closed the door & you guessed it it would not open.Solution was to buy a new latch this was done and fastened in situ closed the door & once again it would not open.Took the latch out again and after several attempts it was discoverd that the latch would operate with the door push button but not if you pushed the door lock button down also everything works with the latch in position but as soon as you start to tighten the three screws it will not operate I & others are at a loss as to what to do.Has anybody else had this problem & if so what is the solution to the problem.I AM DESPERATE FOR AN ANSWER PLEASE.

[north]

Sounds like a problem I had with a 69 fullsize door latch (probably the same design latch).

My case was that the latch worked fine unless you tried to open the door (from inside or out)when it was locked. If you then tried to unlock the door you couldn't fully release the lock pull knob. After several latch degreasing and relubes it would happen less often put still occasionally did.

I found the problem by accident, there is a plate that comes out of the latch itself and interacts with the locking lever rod. On top of the latch there is supposed to be a small spring that insures that when you unlock the door that plate drops back down (It goes up when you lock the door with the key or the pull knob).

As I was cleaning the bottom of the door of excess degreaser I found a broken spring. I opened up the passenger door and sure enough I saw that that plate was pushed down by this little spring on top of the latch assembly. Unfortunately I didn't take pictures.

[north]

I found this picture online, may not be exactly like yours but they are all the same conceptually. The red outline is the plate I mentioned that must drop when the door is unlocked (It is lifted when the door is locked). The blue outline is the spring in question, it's purpose is to push that plate down when the door is unlocked. If the spring is broken or missing the latch can still sometimes work because gravity will help the plate drop. If it doesn't drop freely though it creates that lock out situation because if if doesn't drop you can't unlock the door fully and the latch is trapped in limbo. Before I replaced the spring and after I cleaned the hell out of the latch and regreased it I was usually able to get the door open by yanking and jiggling the door lock knob repeatedly until the plate would fall. With a new spring (Actually I pulled one from a spare door I had kicking around) it works perfectly.

[Dave from England]

Hi North,

Thank you for your reply and willingness to help. Unfortunately my problem is not what you described as you will see from the photographs of both the old and the new latch, they both have the spring you mentioned in tact.
My problem is that everything works when the latch is located in position with the three screws in the holes as pictured, but as soon as I start to tighten the screws to make the latch secure then the latch refuses to work.
This is the same latch as used on the '67 Camaro and they must have mad thousands of these!! So, someone must have had the same problem as myself. I just hope that the solution isn't "buy a new door" LOL

[Dave from England]

SEVENTY THREE VIEWS & ONLY ONE RESPONCE not having a lot of luck am I.

[JimFB400HO]

Dave, Maybe you could also search previous threads and ask over at the 1st Gen Firebird and Camaro websites:

https://firstgenfirebird.org/forums/

and

https://www.camaros.net/forums/

[north]

I would try a process of elimination...

Did the first door latch look original and never removed? If not could the three screws be too long and are hitting something inside the latch?

Also how are the door hinges? If they are worn the door could be mispositioned and the door striker could be in the wrong position in the latch when closed.

Is the car a convertible? These cars tended to sag in the middle when rust got into the subframe mounts or the rocker panels. This could cause the same problem as the hinges being worn. It can happen with coupes as well but it takes heavier structural rust to lead to this same outcome.

GM X and F bodies of that era were notorious for body distortion from rust. Have a good look at how the door lines up with the fender, quarter and rocker. Compare it to the other side also. If there has been some corrosion related shift you may be able to buy a bit of time by adjusting the striker (moving it up, down, sideways or adding or subtracting shims to it.

[Dave from England]

Thank you to both Jim FB400HO & north for your responses.to answer your questions The car has undergone a no expense spared nut & bolt restoration that was finished in 2018.The car is a convertible but was braced throughout the whole restoration which included media blasting a powder coating the sub frame replacing the whole floor plus trunk floor .the door hinges were refurbished with new pins.Both drivers & passenger door latches are the original ones as is the hardware.There is not a speck on rust on the car anywhere it is like new is kept indoors when not in use & has been indoors constantly since last September due to the weather & covid 19.Both door latches have worked perfectly from October 2018 when the restoration was finished until that fateful day in September 2019 during which time the car has been driven 2500 miles.

[north]

Good to know it isn’t structural. Could the striker or a hinge have shifted? (Not properly torqued), also new bushings can pop out letting the door sag.

How is the alignment of the door when closed and how does it feel as it closes (is the door coming in low but the striker forces it up as if closes for example).

[Dave from England]

I don't have to even move the door for the latch to stop working. With the door open and the latch located in position & the three screws holding it in place with just a couple of turns everything works without shutting the door.As soon as I tighten the three screws to secure the latch the door pull refuses to move either up or down.

[north]

Then I lean back to the possibility the screws are too long? What if you tried to install the latch with just two screws, tighten it in place in each of the three possible combinations of 2 of 3 screws installed.

Another possibility is that the door in that area is deformed and tightening the screws distorts the latch.

Last possibility I can think of is that some part of the lock linkage is wrong or deformed and is causing a problem.

I’m assuming the problem isn’t the latch as you mentioned you’ve tried a second latch with identical results.

[Dave from England]

The screws I am using are the original factory screws but even so if I was using screws that were too long I don't think that would be a problem as they wouldn't foul anything.Ive discounted the linkage causing the problem as it has worked fine for two years without a problem.So Im of the opinion that the door panel that the latch scews to is not flat.I am having two pieces of quarter inch thick steel laser cut to the shape of the latch along with the locating holes one for inside where the latch is mounted & one for the outside opposite it so that I can screw in some longer screws with the same thread and hopefully pull them together so making sure the sheet metal in that area is flat.Then I will try again.