S&G Lock Becoming Unreliable

[sign216]

I have a 6700 series S&G lock on a cabinet style safe, and over the past year it's become unreliable, sometimes taking three or more tries before opening on the combo. What should I look for?

I took the drawer out and opened the lock. Nothing obvious, although the spindle key was set to RH, when it should have been set at VD (vertical down), since the bolt is positioned downward.

History: This is an old two drawer cabinet safe from the Navy, that originally came with an electronic lock, an X-07 I think. 5 or 10 yrs ago when the electronic lock got unreliable I replaced it with a used S&G 6700 series lock, and reset the combination. It's been fine until recently.

What should I look for as I examine the errant lock?

Joe

[MartinHewitt]

A reason might be wheel slippage, i.e. the number a wheel is set to shifts. If you can have a look into the lock then you can dial in the combo without the final right turn and have a look if one wheel is misaligned. Also a fly could get stuck sometimes. The dial ring could be loose, or the spline key. A full service would be a good idea. This thing is a pain to open in case of a total failure.

[sign216]

MartinHewitt, thanks for directing my attention. It looks like the middle wheel slightly turns when the third (last) wheel is picked up. Moves just a hair, but it's enough. Also, two wheels may have slipped 1/2 number, but it's hard to tell.

I am leaning towards getting a new lock body. MBA is showing them for $90. If the repair was simple and direct, like a loose spline key, dial ring, etc, I'd be game for the repair. But digging into the internals is beyond me, and I'd rather open my wallet for a new unit.

Looking at my records, I installed the lock 4 yrs ago. It was bought used, and the sticker shows it was manufactured 7 yrs ago in 2016. So it's not that old, but it has an unknown history.

I am open to ideas, if I am going down the wrong path.
Joe

[MartinHewitt]

Installing a new lock is the safe way. Maybe someone but grease inside, but I had here also a new La Gard with a stuck fly. This one was ok after a full disassembly and cleaning.

[sign216]

That's an idea. I'll disassemble and wash w solvent. If there's a change in performance I'll report back. If not, then go w a new lock. Thank you.

[billdeserthills]

MartinHewitt, thanks for directing my attention. It looks like the middle wheel slightly turns when the third (last) wheel is picked up. Moves just a hair, but it's enough. Also, two wheels may have slipped 1/2 number, but it's hard to tell.

I am leaning towards getting a new lock body. MBA is showing them for $90. If the repair was simple and direct, like a loose spline key, dial ring, etc, I'd be game for the repair. But digging into the internals is beyond me, and I'd rather open my wallet for a new unit.

Looking at my records, I installed the lock 4 yrs ago. It was bought used, and the sticker shows it was manufactured 7 yrs ago in 2016. So it's not that old, but it has an unknown history.

I am open to ideas, if I am going down the wrong path.
Joe

What's wrong with saving money?

https://mbausa.com/4-wheel-mechanical-lock-ul-group-2/

[MartinHewitt]

If trying to safe money:
https://mbausa.com/3-wheel-lock-dial-ri ... thickness/

[sign216]

I took the lock, whole, and washed it in acetone. The body paint took it fine, but the solvent took off the print on the lock labels. There was no obvious grease or dirt that the solvent washed off, but who knows.

Re-installed the lock and checked the combo and operation. The combo middle number is now off by two. Not sure when or how that happened. However, with this new combo, the lock worked 19 out of 20 tries. Success!

Two questions.
1. Spline key is at RH position, even though the bolt is vertical down. Does this matter?
It was at RH when I opened it up this week, I must have made an error years ago when installing.

2. What's with the combo middle number being off by two? How does this happen? The only pieces I took off were the drive cam and the lever arm. Could this number migration have been the original issue to begin with?

Joe

[MartinHewitt]

There is the "forbidden zone" for the last number. If the last number is in this range it may create problems immediately, in a few years or never. This forbidden zone is often 0-20 (depending on model and dial). But it is only there when the spline key is in the correct slot. All other changes don't matter.

Usually it is the last number, which wanders, because it is most used and clashes directly with the drive cam which is connected to the dial. Can't say why your middle number is off.

[sign216]

Martin,
The last number is 21. Just outside of the zone. The middle number is 36, but shifted to 34. I don't know why. It's reliable at 34. I'm getting a change key on Tues, and I'll change it back to 36, if everything works as designed.
Who knows? Any ideas?

Joe

[Raymond]

Interesting that the second wheel would now be off more than before. Perhaps the change key socket is turned slightly allowing the gear teeth to slip? When you get the change key set the combo again and check for problems.
Is one wheel still turning a bit when the other is picked up?

[sign216]

Interesting that the second wheel would now be off more than before. Perhaps the change key socket is turned slightly allowing the gear teeth to slip? When you get the change key set the combo again and check for problems.

Is one wheel still turning a bit when the other is picked up?

Raymond,
It's the middle wheel (2nd number) that turns when the last wheel is picked up. After washing, now it usually doesn't happen. When it does happen, it's very slight, almost just a vibration, and the middle wheel doesn't move enough to foul the combo.

It is odd that the middle combo no. would change by 2 digits. In the whole lock, it seems like the middle wheel is the problem area.

Joe

[billdeserthills]

I usually find that changing to a new, different combo fixes this problem, if not it's time to toss that lock & replace

[sign216]

The lock, made in 2016, has been in place for 4 years. The safe gets light use, opening approx. once a week, and it's taken those 4 yrs for the problem to arise. Not a good track record. The solvent wash may have solved the problem, or not, and just brought it back to the orig. condition.

Bill, Thanks for the combo change idea. When I get the key next week I'll do that, and report back. Although It might take another 4 years to know whether it's fixed or not.

Joe

[8550jim]

Take a look at where the spindle is splined. The dial shown is a common dial for an 8500 series lock, you have a 6700 series lock. They use a different spindle. As I recall the 8500 series is splined at 18 or 19 while the 6700 is splined at something like 41 or so. This is from memory and may not be exact, but they are different. This may be why you put the spline key in at a different place than the actual mounting position. Just something to think about.