We live in a house originally built in 1937. A few of the interior doors have what I believe are called mortise locks. They don't work terribly well but I'm reluctant to replace them, if that is even possible. I have not attempted to pull them out of the doors yet but am wondering if anyone has any experience with these. Are they something that can be repaired/refurbished? Do I need to take them to someone? If so, who would that be - an old school locksmith? Pictures below.
The actual lock works perfectly fine. It's the doorknob function that is pretty non-functional. Turning it one way starts to bind while turning it the other way mostly engages the catch.
I only have passing experience with these (our previous front door had one), but I'm holding out hope that you'll find the issues on removal and inspection.
If like mine, not hard to remove. The weirdest bit IIRC was some of the shafts don't pass though but are split and, er, hooked, so to disassemble you remove the knob, then pull half the shaft out, then there's room to pivot the other half so it can be unhooked from the hub. Yours may not be so archaic/complicated.
I never had to dig into the main body, so I'm afraid I'm no help there.
I did a few of those on my old house. They're pretty simple and straightforward to work on. Biggest thing is lubing and making sure nothings too tight or too loose. The symptoms you describe are likely the door knobs being too tight. Loosen the set screw and unthread the knob on the shaft a quarter or half turn then retighten the set screw and test it out. Also drop a tiny bit of oil between the knob and the escutcheon (the plate that goes between the knob and the wood of the door).
You can pull it apart and see if anything is bent but at a guess, it just needs some lube and TLC. It's probably still operating on 1937 lube.
They are replaceable. With some careful measurements, you should be able to order one with the same mortise size.
Usually the set screws on the knob gets loose and spins on the square shaft. If you loosen the set screw the knob will unscrew and you can slide the square shaft out. This allows you to remove the lock to clean and lube. Once you get the parts out, you can see how worn the square shaft is in the mating square hole. I have swapped parts between high-use doors and closet doors to help with slop. Van Dyke's (https://www.vandykes.com/) has parts.
I took all the screws out everywhere but the knobs still feel very firmly attached. Should they just pop off now? I'm worried about forcing them off.
In reply to dyintorace :
No. Those are on a square shaft that is threaded. Once the set screw in the collar is removed, you still have to unthread the knob from the shaft.
They are super simple machines with pretty poor machining but enormous tolerances.
The knob will unthread, the shaft will pull through, then the entire mortise lock can be slid out of the door.
Before disassembling the mortise lock, lay it on a table with good lighting and take it apart slowly. Watch carefully- the pieces may all spring out and then it will be hard to reassemble if you weren't paying attention. Live up the internal parts and reassemble.
The adjustment you are looking for is what Toyman described. The knobs are threaded too tight on the shaft, and the set secrets loosened.
You'll need to log in to post.
