[Superhart]

I decided to attempt to modify a passenger side latch on my 1930 Model A coupe to accommodate a sliding lock mechanism. First, I placed an order with Snyder’s for a new set of latches along with a sliding lock, lock knob mounting screws and escutcheon. When the parts arrived it appeared that this might not be such a complicated modification after all. Look at the first photo and you will note the basic differences between the driver (left) and passenger (right) latches. The backing plates are already stamped the same providing the trough that the lock bar slides in. On the left hinge the lock bar slides in a trough and is held in place by a small retainer that is tack welded in place. The bar is spring loaded. The spring is difficult to see in the photo because it is wrapped around the small post shown and is hidden by the latch spring. When you slide the sliding lock button on your door, the lock presses against the lock bar mounted on the latch and pushes it into alignment with a pawl preventing the door handle from opening the latch. Very simple yet quite effective.




The first thing to do was to cannibalize the left latch to obtain the parts I needed to mount on the right hinge. I began by carefully drilling through the tack welds on the lock bar retainer until it popped free. Then I turned the backing plate over and noted that the small slotted post I needed was peened in place like a rivet so I carefully drilled until I was able to extract the post from its mounting hole.



Using the cannibalized left latch as a guide I located the mounting hole for the slotted post and used a #11 drill bit to drill the hole which was a good press fit for the post. On the exterior surface of the right latch I slightly beveled the edge of the mounting hole to provide a little more room for the weld needed to secure the post.





See the photo below of the four parts removed from the left latch needed to install on the right latch.



Next, I installed the slotted post in the drilled hole in the right latch and tack welded it in place from the opposite side.



Finally I will place the lock bar in the trough and tack weld the retainer. The lock bar spring will be installed to complete the modification. I will post the final photos when available.

I decided to leave the left door sliding lock operational so, if needed, I could lock both doors while driving. Yes, I realize there is a possibility of locking myself out of the car and having to break a window to get in but I will take that chance. I will post further photos and text as the project progresses. I now need to remove the right door interior trim panel, mount the sliding lock mechanism, cut an access hole in the rim panel and install the escutcheon. I hope that this narrative and photos will prove helpful to anyone who has thought about installing a slide lock.