Late '40s front door locks

[DeS-11]

I'm hoping that someone can help with an issue I'm having with front door locks, specifically on a '47 DeSoto. At first, both outside cylinders would just turn 360 degrees without any effect, although both doors would lock with the inside handles; I later determined that both cylinders' square rods were just hanging inside the doors, not connected to the corresponding square holes. I reinstalled both according to the service manual procedure, first turning both square holes to the far rear (unlocked) positions, then turning the cylinders with the key 1/4 to the rear (the cylinder's stated "unlocked" positions), and installing them in the doors, then tightening the set screws. At that point, the locks functioned from the outside with the key, but here is where the issues began:

 

1. I installed the cylinders with the wider part of the outside bezel at the top, so that the swing-down cover pivots at the 12:00 position, which seemed the proper way to do it. However, I found that, now, when turning the cylinders to the front of the car to lock the doors, the key ends up right-side-up and can be removed, yet when turning it to the rear to unlock them, it ends up upside-down and can't be removed; it isn't 1/4 turn from vertical in either direction, as the manual states it should be, and then returning to vertical (with the door locked or unlocked) to remove the key. There is still the 180 degree range of turning as would be expected, but it's either all the way right side up and locked, or all the way upside down and unlocked, but unable to remove the key when unlocked.

2. Now, unlike previously, the inside handles don't operate the locks, and you have to actually reach out the window to unlock the door with the key in order to open the door, unless you leave the key (stuck) in the cylinder with it in the "unlocked" position. I should note that I didn't remove or adjust anything relating to the inside handle mechanism; the cylinders were the only parts removed, and the inner square holes were just moved manually with a screwdriver, per the service manual procedure.

 

So can anyone figure what I might have done wrong? It seems that everything "should" work, but obviously something is off--and whatever it might be seems to be the same issue on both sides.

 

 

[Plymouthy Adams]

if I recall when locking via the key you turn it to the lock is set condition,  then return the key to neutral position for removal from the cylinder.

Edited June 24 by Plymouthy Adams

[DeS-11]

That's how I understood it, as well. But for some reason mine only unlocks in the "key upside down" position, or locks in the "key right side up" position; starting from vertical and then going 1/4 turn to either side and returning to vertical, as the manual says it is supposed to be done, doesn't produce the correct operation (most likely due to my installation error, but that's what I'm trying to figure out). I still wonder, also, why the interior handles would have worked correctly to lock or open the doors when the square rods weren't in place, but now that they are, those same handles have become inoperative. I wish the manual would be more in-depth on the workings of this system; while it's helpful to have, it's somewhat lacking in detail. 

[Roofus]

Quote

I installed the cylinders with the wider part of the outside bezel at the top, so that the swing-down cover pivots at the 12:00 position, which seemed the proper way to do it.

You are upside down.Normally cutting in the sheet metal only allows the right position ... And the square holes of the lock are probably not centered

Edited June 25 by Roofus

[DeS-11]

That may be; I'll have to try some repositioning when I have a chance. Mine actually has three notches cut into the sheet metal, which correspond to three tabs cast into the cylinder. However, I think that they're the same distance apart, so that it could be inserted at three different angles and still "fit." Does anyone have a latch/lock assembly out of the door that they could post a photo of so that I could try to visualize how it works?

[DeS-11]

I found that the solution was to, with the square holes turned all the way toward the back, position the key in the cylinder at about the 1:00 spot (left side) and 11:00 spot (right side)--about 1/8 turn--as opposed to the 3:00 and 9:00 spots (1/4 turn) that I had been using, then install the square rods and the cylinders into the doors. Why this slight positioning adjustment made such a difference, I'm not sure, but it resolved it and both now work as designed, from inside the car and out. The service manual doesn't mention this starting position, but it probably was obvious to someone who worked with these all the time. In any case, I just wanted to provide an update for any future readers of this.

[desoto1939]

here is some info on the 47 Desoto locks taken from my Briggs and Stratton catalog.

Rich hartung

desoto1939@aol.com

 

[DeS-11]

Thanks, Rich; I've added it to my notes.