Locking mechanism guide for potential sticking/not opening problems

I purchased a new locking mechanism some time ago and it never quite worked right, getting stuck after locking, and not opening anymore.

I had a look around here and other places and couldn't see much on the internal mechanism issues/fixes online so thought I'd add to the lot and give my 10 pence.

This is a rough guide on what I discovered after staring at it for a while and pinching the ends of my fingers alot to figure out the mechanism.

I won't go into how to remove and replace, there's plenty on that. 6mm Allen key, pull free, fiddle and twist hook off bottom arm, carefully to not scratch things too badly.

The locking mechanism I purchased was off Heritage for £8 and I got what I paid for.

The problem was apparent after shutting the door and locking it, it wouldn't unlock properly and release the latch.

What I found was that the metal parts were misaligned after some use, meaning that when locked, the opening arm (right hand side, running vertically) was pushed forward and getting stuck on the inside door handle arm (lower horizontal 'U' shaped bar along the bottom on the pic), meaning that when unlocked, it stayed in the locked position and could not release the latch.

In the image (I took it after I bent it back into shape) you can see where it unseats and sticks.





To fix this, I pushed the lower part of the arm towards the spring, left when looking at it (using a screw driver and a bit of force) being careful to leave free play and not mingle with the springs and such, to give it enough play to lift and push forward when locked and reseat/return to open position once unlocked.



When unlocked, the arm then sits back and is able to catch on the latch (poet; didn't know it) when the handles arm is depressed (physically, not emotionally).



When the handle arm is depressed, it will then release the catch and the door will open.



There's not alot more to this, just enough to help future me potentially fix a common problem that seems to exist with these locks (it's not my first locking rodeo).

Please let me know if I'm talking codswallop, I'm learning as I go (aren't we all), I'm a desk jockey email reader for a living and doing this sort of stuff has gotten me through the lockdown blues (although I haven't managed to save much) and helped with my mental health.

Hope it helps, feel free to say hi any time!

Its close but well a wee bit off, and that could be why it worked IFFY.

OEM.


It also needs a tad bit of grease.