Door Latch Replacement

[Mumbles]

Hello all...

I'm replacing the driver's side door latch on my 79 Firebird.  The outside door handle seems to require more "umph" than I like to put it thru in order to get the latch to open and I don't want to risk damaging it due to a sticky latch.

I have the door panel removed and the interior door handle rod disconnected from the latch lever, however getting the 3 mounting screws on the door jam side of the door to come loose has been frustrating, to say the least.

I've been blasting the threads with some penetrating oil for the last couple weeks, but despite all my attempts, I can't even get one of these buggers to budge.  I'm using the proper #3 Philips bit as to minimize striping the head.  I've tried an impact driver and a mallet, a regular nut driver, a bit in a 1/4" socket with a ratchet and a few other "creative" assemblies that I thought may do the trick, but as I said, nothing has worked.

I'm to the point where I'm planning to drill thru the heads of each of these screws.  But prior to doing just that, I thought I would inquire with TAC to see if there are any members who have a trick they've used or any bit of advice to lend.  I'm all ears.  Thanks everyone.

[737driver]

I used the LISLE impact driver that is used with a hammer and that did the trick. They are tough to remove, but using the impact driver and hammer is the only method I used that worked.
Jim

[81Blackbird]

That is what I used on many applications.  Worth the money and time for sure.

[Warren Seale]

I'll bet that you can fix that difficult latch by flushing it with degreaser and then lubing it again.  Have you tried doing this first?

[Mumbles]

Thanks for the replies everyone.

I don't disagree that the latch is probably just in need of some lubrication.  However it is over 40 years old and rather than wait for a complete failure to the point of no longer being able to open the door or it not closing, as well as the risk of damage to the outside door handle (for which I cannot seem to locate the correct "Carmine" color insert), I thought it best to replace.  Plus waiting longer isn't going to improve the chances of seized fasteners coming loose with ease.

After failing on my first attempt to remove these screws, I did a little looking and found a YouTube video that showed a technician using an Impact Driver and purchased this one from Mr. Bezos.

https://www.amazon.com/dp/B000NPUJYE?psc=1&ref=ppx_yo2_dt_b_product_details

This is my first experience with an Impact Driver.  Unless I'm missing something, this one seems to function as designed and I believe I'm using it correctly.  Driver is set to "L" for counterclockwise rotation, I place it in the screw head with a little pressure in the direction I want it to turn and strike it with a hammer.  Not too complicated.

As I said in my first post, I've been hitting the threads with some penetrating oil off and on for a while now.  I'll give the Impact Driver another chance and hope this combo of lubrication and force does the trick.  If not, I guess I'll bust out the Dewalt, some fresh HFT drill bits and my Drill Doctor.

Thanks for the comments everyone. 

[FormTA]

To use a hammer impact driver insert it into said screw and
twist it in the direction you want it to go, it should be tight keep that tension as you hit it with the hammer. The tension you put on it by turning it makes the impact more jolting as it's not getting absorbed by the internal mechanism of the impact driver.

[firebirdparts]

I agree with the impact driver. 

By the way, I found that the new latch was unlockable in a lock-then-close order of actions, like a Toyota (for instance), and this clearly runs afoul of the way Firebird door locks were intended to be used.  I may regret this some day, but I figured out how to disable this by mangling part of the mechanism.  I can't tell you how I did it, I can just tell you that it's possible.

[Gene-73]

I tried all the methods including the impact driver. Nothing worked so I ended up drilling mine out.

[Warren Seale]

Instead of using the proper sized Carmine handle insert, try looking for wide pinstriping in that color.  That width should be available in pinstriping.  You may not be able to find the exact color but something close should be available. 

[Mumbles]

I agree with the impact driver. 

By the way, I found that the new latch was unlockable in a lock-then-close order of actions, like a Toyota (for instance), and this clearly runs afoul of the way Firebird door locks were intended to be used.  I may regret this some day, but I figured out how to disable this by mangling part of the mechanism.  I can't tell you how I did it, I can just tell you that it's possible.

Mm... well this information is very intriguing. Do you happen to know what brand of latch you purchased?

I have a Goodmark set from Summit.

https://www.summitracing.com/parts/gmk-4021-444-77l

I don't think I'll be happy with an $80+ latch that doesn't perform the way the factory piece does.  I'm gonna have to see if I can test the ones I have.  If they're gonna do what you described (unlock as the door is closed), I'll just do what Warren has suggested.  That is, lubricate the originals and call it a day.

Thanks for the heads-up on that firebirdparts.