Working on nightlatch style locks - troubleshooting

[zeke79]

I have only worked on this style of lock a couple times. In each case they must have been improperly installed as the tailpiece of the rim cylinder was putting the plug in a bind causing hard turning keys. I have noticed in one case the boring for the mortise cylinder was crooked so after straightening it out all was fine. However, i worked on one today that seemed to be bored straight and installed new cylinders and never could get the lock to be totally bind free. The keys turned easy but not as easy as I would like. I made sure the tail pieces were not too long, everything was aligned properly, etc.

I would love to hear how others here troubleshoot these things to ensure smooth operation.

Here is a link to the type of lock I am speaking of.

http://www.actfastlocksmith.co.uk/produ ... number=528

[DaveAG]

At least on the one I have, if you take a look at the "face" of the lock itself that is up against the wood of the door, you should see a cross shaped hole for the tailpiece and a screw that holds the plate down.

If that screw is too tight, there will be friction when you turn the key.

You can of course test the friction by turning the lock with a screwdriver where the tailpiece would go. Try it with both the door open and closed and you will be able to see if the bolt is binding, or if the plate is too tight etc.

[JackNco]

thats almost exactly what i have on my door. very common locks in the UK. ive never noticed this problem on one but im installing one on a lock board in a couple of weeks so ill know more then.

[zeke79]

Thanks guys. I'll keep this in mind when working on these locks again. I feel it must be the prior installations that are bad on these as they are very tight to turn when I get there to work on them.

[RangerF150]

I install them with my eyes shut! And never have a problem.
There is actually quite a bit of latitude or play in the positioning of the cylinder.
The tail piece needs to be cut so that it enters the lock only by about half an inch or so, after that the only reason it will be stiff to turn the plug is that the cylinder is to high / low or to much to the left or right.
This you should be able to do by eye, or use an adjustable square.

If everything is fitted and "cast in stone" IE you can't move it, you could try file the tail down just a little in one side or the other if that's where the problem lies, I would not file too much ( it's something I never had to do, as I note there is a lot of play in these locks, but it might help, a better solution would be to open the hole a little more.)

The hole size for the cylinder should allow the cylinder to freely fit in the door, there should be some play there.
The cylinder retaining bolts should not be overtightened to the point where they deform the retaining plate.


There is nothing there that you ain't covered already, so I am at a loss to explain you plight!

FedEx the door and lock over and I'll have a look see

[NKT]

The biggest issue is that retards who think themslves locksmiths install these things and get it badly wrong! I don't know how anyone could drill a 32mm hole that is supposed to be centered at either 40mm or 60mm from the edge at 50mm, but I have seen it done. And, needless to say, I couldn't get the lock working smoothly!

You can test the lock easily with the door open, so the strike isn't going to be an issue. Test it first, then shift the strike if you need to. Test the lock's function first, then check the tail piece for length. On the cheap backsets, you generally have a huge void for it, so you won't have problems, but the high security ones, especially the ERA ones, need no more than about 8 to 12mm sticking out.

You can do the cylinders screws up onto the backplate about as tight as you like, without getting silly, and you shouldn't have any issues unless it starts to deform. This is because the actual latch part is held in place quite loosely on two hooks, and then held in place by two screws, so the placement isn't a tight toleranced thing.

I can't believe I've written this much about fitting one of these! I've fitted the cheap ones in less time than it takes to type it out! One big hole, 6 screws, one mark, and three more screws, if it is a badly fitting door. Bit of chisel work if it is a tight fit.

[zeke79]

Thanks everyone again.

Nigel as you say, the one I knew was due to poor installation and the hole was bored crooked so when I screwed the back thumbturn down tight the angle of the tailpiece was putting the plug in a bind in the shell causing stiff turning keys.

The second one I done just yesterday was A. installed upside down and b. I bet like you said installed too far away from the strike or too far back on the door. I wanted to move the lock a bit and fill the old screw holes but the owner (my mother ) did not want that done. There was really nothing I could do with it as I messed with it for about half an hour or so and got it smooth but not as smooth as this type of lock I have installed fresh on an old style door (why they wanted this type of lock I dont know. No offense to the UK guys but these are not really common in the US that I have seen).

I agree with you guys. I have installed a set of these at my fathers home a long time ago and they went in like a dream and worked flawlessly. I guess these matched the "decor" better to him. I think as everyone says, the problems are due to a very poor installation.

On another note, in the UK I assume these nightlocks have a deadlocked feature? On the two I have serviced there was no deadlock feature whatsoever.

[JackNco]

The night latch completely locks the mechanism. you cant use a key or even push the bolt in. do the ones you have installed not do this?

[zeke79]

None of them I have worked on or installed have this feature no. These are cheap junk locks. Next time I am around my moms place I will try to look at the brands. IIRC though one of them I worked on yesterday was harbro maybe?

[JackNco]

oh right, the image you linked to has it thats what confused me. the small latch that looks like a button by the main latch. that pushed up or 2 the side and locks it all in place at night time. useless on the lock i have as its mounted by a windows but good on solid doors. also means you can set the bolt back in the lock and press the latch so the door doesnt lock when you close it.

[raimundo]

Zeke, in that photo that you linked to, there is a piece of the installation not shown. that is the back plate that the mounting screws go on, this will have two holes for the screws and a pass through hole for the tailpiece, when these locks have been replaced with another similiar type, sometimes the installer will not put the new back plate on and will use the back plate from the previous lock. the orientation of the holes on this back plate can have the screw holes higher or lower in relation to the pass through hole, and sometimes they are even wider apart or closer together. this can cause problems. you mention that the tail piece was not too long, this is of course another of the problems that can occur.
rim cylinder locks come in both deadbolt and latch. with the latch having an interior button that is typically moved up or down to keep the latch from locking or to keep the latch from opening with a key. as mentioned.

[toomush2drink]

Instead of moving the lock zeke you should have moved the cylinder over then you wouldnt have holes to fill.If its needs moving right over you can use a repair rose designed especially for this scenario.This is basically a biiger version of the ring that fits around the cylinder.

[zeke79]

Ray and toomush2drink,

Thanks for that. You both pointed out some very obvious points that I overlooked. Like I said I really do not mess with these locks much. I am going to buy some oversided collars so next time I can move the cylinder over and fix the problem that way.

I used the retaining plates from the new locks so that should not have been the problem. I am going to buy some larger cylinder collars and do some more work next time I am there.

Thanks again everyone.

[Matt-the-rat]

Is this the type of lock that would need a large (maybe 2") 2.5" hole drilled through the door?

[ponsaloti]

In the van I carry repair plates and door pulls which I can use to hide a multitude of sins.I have come across 32mm holes in doors that were drilled by ray charles, also on more than one occasion some-one has replaced original n/latch which may have been a banham or something similar that had a 50mm back-set with a newer n/latch at 60mm. On some real cheap rim cyl`s you will sometimes get a problem with the cyl distorting when you tighten the mounting screws