Late 280z Door Locks

[S30Driver]

Although I have commented on this in the vendor thread about this new lock solution, I thought I would add this here to possibly help 77 78 280z owners in the future.

I recently purchased the new lock set for 77 78 280z's from Zcardepot to mainly address the missing lock arm on my passenger door.  Also, I agree with Capt. O in commending Zcardepot for addressing and providing a quality solution for the difficult to find late lock arms.  And doing it in stainless steel.

Since my lock arm was missing, I opted to see if I could install the new arm on the original & excellent condition lock (no wear on the cam).  It is very close to directly fitting.  I used a round file to remove a small amount of metal from the half rounded surface of the arm where it slips past the lock cam & it firmly seated at the base of the lock.  Replaced the original Nissan clip (I've leaned from Zup the importance of maintaining originality ) lubed with some graphite, re-installed and voila - a perfect functional passenger door lock.  A first for this car since I have owned it.

I will have the new locks re-keyed for my code, and then switch out the driver side which has the cam wear and repaired with the coat hanger modification.  All that is required is the locksmith have the caps & shutters.  I think the oem locks can be disassembled and retain those parts.

The only other addition I made was to install a small piece of rubber tubing on the arm where it contacts the door mechanism.  Not necessary but I thought it might reduce wear.

Locks appear to be good quality with a stainless steel arm & new gasket.

 

New lock dis-assembled       You can see there is no return spring on the lock assembly

Original lock with new arm installed

 

[wheee!]

Nice writeup!

[Captain Obvious]

Nice. Not as tight of a fit on the shaft as the original arm, but looks like it would work.

One other thing to consider though... Are you sure you've got enough linkage travel to lock and unlock the door? I don't remember how much dead travel there was on the original version, but since you're adapting one hole style to another shaft shape, you might have changed the amount of travel.

Also might be nice to take a good close-up pic of the centering springs for those who aren't familiar. I took a look through my old lock pics (get it?) and I didn't take any of those. I was in such a hurry to get my locks back together that I didn't do a great job of documenting my work.

[S30Driver]

It appears to be not as tight a fit as the originals because it looks like the new arms are made to be universal for either the driver or passenger lock.  If I remember, the originals were different to accommodate the change of the lock cam direction from one side to the other.  I filed the narrow part of the arm where it goes around the cam.  It is very tight - just enough to seat at the base of the lock.  (I know it's hard to visualize from the picture)  Also, the travel is now reduced due to the rubber I added over the thin part of the arm where it moves the latch mechanism.

I'll get a picture of a lock with the return spring and add it to the post.

[Captain Obvious]

Yup. The ability to use the same arm on either side went away when they changed to the 77-78 design. With the later design, the lock body itself is interchangeable to either side, but the arms are unique to each side. It's all because of the shape of the shaft sticking out the back of the lock body and the corresponding hole where the arm goes onto the lock. The shaft and hole on the early design is symmetric, but the hole on the later design is not.

 

I'm not sure why they ever changed the shape of that linkage, but if I had to guess, it was because they were trying to fix the issue where the back of the lock body would deform and smear with use and not work anymore because it had become too smooshed. (The reason you used that coat hanger fix.)

 

I would surmise they believed the new design was more robust than the early versions. I don't know about how many lock cycles you get for each design before they fail, but I do know that the later designs do eventually suffer the same fate as the earlier versions. It may take more cycles to get there, but they all eventually fail in the same sorta way. The big difference after all these years, however, is that you can replace your early design locks with cheap replacements. And until the new product offering from Zcardepot that was no replacement option with the later versions.

 

So what may have been an advantage of having a more robust design is actually now a hindrance (until now) because you can't get replacements. I expect that Zcardepot's locks will fail in the exact same way as the early version locks did, but at least now you can repair or replace them when that happens. And you and I may be dust by the time that happens.

 

As for how your modified arm fits onto the lock, I say it's not as tight as the originals because of the gaps on the sides. It's been a while since I looked at lock stuff, but I believe that the originals fit more snugly on the shafts. I thought the only gap was where the dead travel was needed. I have a box of lock stuff around here somewhere and I might have some of the new design locks. I'll take a look when I get a chance.

[sweatybetty]

1 hour ago, Captain Obvious said:

 The big difference after all these years, however, is that you can replace your early design locks with cheap replacements.

so these will fit a 72?

[SteveJ]

1 hour ago, sweatybetty said:

so these will fit a 72?

No, but you'll find plenty that do on eBay. Also at Z Car Depot: https://zcardepot.com/interior/door-parts/door-locks-cylinder-lock-w-keys-70-76.html?search=door+lock