Chubb manifoil mark IV question

[Lloyd]

Hello Everybody. First post and I'm after a bit of advice on a small safe I have just purchased.
It came with a Chubb Manifoil Mark IV lock. The combination was unknown but it was unlocked and came with instructions on how to find out the code and how to reset it. I have a reset key.
I have worked out the code and today I reset it. I made sure I could open it a number of times before locking the box. I have since had trouble opening it. I'm sure I'm unlocking it correctly but you get to the end and the bolt does not open. After many attempts of trying the same code it opened so I have sprung the bolt and left it open.

The lock is dated 1978 and looks like its not been used for a number of years. Having said that it's in good condition. Do you think it just needs a clean/service inside?
I am a complete novice where locks are concerned and don't really want to use the lock unless I'm confident I can get the safe open again. Is this something a newbie could do or does it need to go to an expert?

Thanks in advance.
Lloyd

[The Lock Artist]

According to the internet, the lock should have the normal operation for a combination lock. The combination has four numbers and is dialed as follows

five turns clockwise to the first number
four anti-clockwise to the second
three clockwise to the third
two anti-clockwise to the fourth
then turn clockwise about half a turn until it opens

If that doesn't work then there is obviously something wrong with it. I would call a locksmith if you want it fixed.
There are websites that will give you more information on the safe, but I doubt you will find information on how to fix it, and if you did it would probably be too complex for someone who didn't have lots of knowledge on locks. I don't think safe work is something for newbies like you and me.
A google search can take you to pages that will give info on the lock like this one:
http://www.codesmiths.com/shed/locks/manifoil.htm
Don't take anything I say as a definitive answer though, I'm a newb compared to most people here, and there are lots of people more experienced than me.

[Lloyd]

Thanks for that.
The trouble I'm having is that sometimes its opening and sometimes it's not even though I am being consistent with the opening procedure.
I have seen the code smiths website and they have a detailed set of photos of taking a lock apart.
When I put the code in on the marker at 11oclock and remove the cover over the reset hole all the holes are inline so I know I have the right code.
I can't get the back of the lock off at the moment as it requires some very small hex keys but do you think a squirt of WD40 would help?

Lloyd

[lunchb0x]

Do not spray anything into the lock, these have a very fine tolerance and will play up if not serviced properly. The best thing that you can do is get a Locksmith to service the lock for you and go though the proper operation of the lock.

Also the last number on these is always fixed, the majority of the ones that I work on are 25 but can also be 0 and rarely 75, you can not change this number.

[cledry]

Are you sure the problem is not in the bolt work rather than the lock? Does the lock open every time with the door open? If so look for interference with the bolt work, pressure on the end of the lock bolt etc.

[Lloyd]

The lock ends with 0 as its a left hand bolt.

Cledry, I'm happy it's not the bolt as when it does open its a nice smooth action.
When I put the code in then turn anti clockwise to 0 then clockwise to the point the lock should open you can feel a very small ammount of resistance and then the dial just keeps turning. It's like the lock is not catching on the way past.
Of course sometimes it works fine

Lloyd

[Lloyd]

Thanks for your help guys. I've sorted it now.

[lunchb0x]

So do you want to tell us what it was then, might help someone else?

[Lloyd]

I managed to get a very small hex key and get the back off. I could then see the the workings and realised all the latches (don't know what they are called) were in line but not far enough over to drop the lever.
I reset it exactly and tried it again and it was still out on every number. If tried opening it again and going 1 number higher and it opens. You can see it lines up correctly.
To sum up if the code is 30-40-50-0 I just use 31-41-51-0.

Does that make sense?

[lunchb0x]

It's possible that the dial ring is loose and has moved which is why the numbers are off by 1.

[cledry]

It's possible that the dial ring is loose and has moved which is why the numbers are off by 1.

However the change index and opening index move in unison with a loose dial. When a safe combination is checked for centering a single digit either way shouldn't affect the opening. If it doesn't then I suspect worn flies from spinning the dial too fast and the lock probably should be replaced if you cannot center the combination.

[Lloyd]

Someone else I spoke to suggested holding the dial when removing the change key as it could move when removing the key.

Lloyd

[lunchb0x]

It's possible that the dial ring is loose and has moved which is why the numbers are off by 1.

However the change index and opening index move in unison with a loose dial. When a safe combination is checked for centering a single digit either way shouldn't affect the opening. If it doesn't then I suspect worn flies from spinning the dial too fast and the lock probably should be replaced if you cannot center the combination.

Yes, but if it's loose and moving around it can still cause this issue.

Someone else I spoke to suggested holding the dial when removing the change key as it could move when removing the key.

Lloyd

I always do this because you are right, the dial can move and change the last number.

I have also come across older Manifoil's with new a new dial and dial ring where the distance between the change index and opening index is about half a number different, this causes a lot of issues but only happens when the lock has been serviced by someone who shouldn't be working on them.