Oddball lock problem, how to fix?

[sisk]

So I've got this KIK in front of me that I've picked at least a hundred times (and don't know the binding order because I've got about 20 identical locks). Today I went to pick it and picked 2 pins and it popped open. Thinking that the pins must not have been fully reset I reset it and wiggled my prybar to be sure that all the pins had dropped and again picked two pins and it popped open. The next thought was that some pins must be sticking, so I gave it a little graphite, worked it in by raking my pick back and forth again, and picked the same two pins before it popped open again. So I took it apart and made sure I didn't have any too-short drivers or too-long keypins (i didn't) and that the springs were all good (they were). While it was apart I also checked that nothing was sticking (nothing was). I put it back together, and picked the same two pins again, and again it popped open. I know it's not a matter of accidently setting pins either because the two pins I'm picking are 1 and 3 (in a 5 pin lock). I'm never getting back far enough to set pins 4 or 5, and 3 is cut lower than 2 so I can't be setting 2 by accident either.

At this point I'm stumped. I've checked everything I know that could lead to this sort of problem. Anyone got anything else I could check to fix this lock? Not that it's a huge loss if I have to toss out a lock I paid $1.50 for and have gotten tons of practice out of, but I'd like to know how to fix locks as well as pick them.

For reference, I probably have a key for it, but it's going to be in a big pile of random keys so finding it is going to be tricky.

[ltdbjd]

Interesting. You've checked everything I would check. I'm guessing you've moved the pins around to different chambers, and still getting the same results? I'm guessing the top pins are all between 0.160 and 0.180ish?

Is it possible all the picking has caused a burr or metal shaving to clog the pin chamber and that keeps the top pin from falling into the chamber?

[sisk]

The top pins are all different sizes, matched to the keypins in such a way that all the stacks are the same size, so longer keypins have shorter drivers. (I'm sure there's a term for that, but I don't know it). I suppose it's possible that there are barbs of metal clogging up the works, but it seems unlikely to have three chambers all with that particular problem.

[ltdbjd]

It's a balanced pin stack. Kind of odd for a regular KIK. It's a good thing, but many of us just use a standard size. Was it working normally and this problem suddenly occurred?

What happens if you put the bottom pin and top pin into the plug. I wonder if it somehow meets the shear line. I kind of doubt it because if that were the case I'd expect the spring(s) to get stuck. (Just thinking out loud). But something is keeping the shear line free.

Have you replaced the pins and springs? If so, and the problem continues, you can rule out them as being the cause, and need to look at the lock itself. If not, you've narrowed down the problem to them.

If you need extra pins and springs, I'd be happy to send you some.

[tjohn]

the plug could be in the housing backwards

[jimu57]

Possibly the holes in the plug have elongated over time due to putting pressure on the holes at the top where the shearline is. Normal use of a lock won't elongate the holes like when you use a tension wrench over and over.

Jim

[sisk]

Was it working normally and this problem suddenly occurred?

All I can say for sure is that I suddenly noticed it. I pick through this particular stack of indistinguishable KIKs at least three times a week, but frequently I'm not giving it my full attention and just use them to keep my hands busy while I'm watching TV or reading something on my computer. They're all 5 pin locks with no security pins and decent but not great tolerances, so they're pretty easy picks for me. It's possible the problem has been there and I just haven't noticed it, or it's possible that everything was fine last time I picked it.

What happens if you put the bottom pin and top pin into the plug. I wonder if it somehow meets the shear line. I kind of doubt it because if that were the case I'd expect the spring(s) to get stuck. (Just thinking out loud). But something is keeping the shear line free.

The driver pins all protrude the same distance above the shear line when doing that. I've not gotten the micrometer out to measure it, but it looks like around 3-4mm to me, more than enough to usually keep the plug from turning in even the cheapest locks.

Have you replaced the pins and springs? If so, and the problem continues, you can rule out them as being the cause, and need to look at the lock itself. If not, you've narrowed down the problem to them.

I haven't replaced them but I have looked at them pretty closely. I would think that any problem with pins or spring bad enough to cause this problem would be visible to the naked eye. Still, I'll try swapping them out this evening after my kids go back to their mother's house.

If you need extra pins and springs, I'd be happy to send you some.

Thanks, but I have some from my challenge lock. It's nowhere near a full pinning kit, but it's more than enough for this sort of thing.

[sisk]

Possibly the holes in the plug have elongated over time due to putting pressure on the holes at the top where the shearline is. Normal use of a lock won't elongate the holes like when you use a tension wrench over and over.

Jim

That's something I didn't think to check. I'll look at it while I have it apart to swap out pins this evening.

the plug could be in the housing backwards

While I'm embarrassed to admit that I have made that mistake before (once, when I was just starting), that's not the case here. I made sure of it.

[ltdbjd]

If your still stumped, you're welcome to mail it to me for an autopsy. Between everybody's input I think we've hit all the possibilities I can think of.

[GWiens2001]

Pins or pin channels very slightly bent/warped causing the driver pins to not be able to drop into the pin channels of the plug. Just a possibility. A picture of the key would help.

Gordon

[sisk]

I found the problem finally. After replacing all the pins changed nothing I got to looking at the plug. Turns out there was a burr on the inside of the face of the thing that was keeping it from sitting flush on the bible. It looks like it came from an impact. I must have dropped it on something hard at some point or something (yes, I know that sounds ridiculous, but I can't think of any other way this could have happened). Anyway I took a bit of sandpaper to it to get rid of the burr, put it back together, and it's working again.

[GWiens2001]

Thank you for the results if your findings. It is nice when we find out what the issue was.

Gordon