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Locksmithing/lock replacement mosler


QUESTION: Saw your name on a website regarding questions about a Mosler safe. I have a Model 12  Serial number 21306-44.  It still has the original Group 2 (302- 402) lock w a red sticker on the outside of lock cover. Combo still works but, sometimes the 2nd number is off by a number. Do I really need to replace the whole dial and combo? The 3 wheel attached to the cover is plastic but, seems to be in great shape , no wear or chips however, once you remove the back cover 3 wheel and turn the dial alone, it becomes very apparent that the spindle is a bit wobbly.  I believe I can address the wobble but I cannot figure how to remove the 2 splines. The splines appear to be 2 legs attached to a small circular piece of brass, like a miniature bar stool w only 2 legs. The center of the seat portion has a threaded hole in the center, as if it was meant to use a screw to turn in and apply  back pressure of the screw to force the splines out .  Hopefully I explained myself well enough. Can you offer any suggestions. I believe the crux of the issue is that the center shaft hole in the center of the lock body may now be out of round and is allowing the spindle to not turn true.

if i need to replace, do you have a suggestion? big red, sg, etc


Gary J Belanger

ANSWER: Hi Gary,

That's exactly how the spline key was meant to be removed.   In fact it is threaded to match the cover screws.

winding the screw in will pull the spline key out.   Be careful as you do not want to break off either leg as this can be a real pain to remove.

My first recommendation would be that the entire lock, dial and dial ring needs to be carefully inspected and serviced.   All mounting screws need to be tightened, ensuring the lock and dial ring are correctly aligned.

If after servicing the lock and resetting the combination to ensure it is accurate, if it still won't dial up consistently, THEN you might want to think about a new lock.

As far as replacements, you can use anything that you want as long as it matches the mounting foot print of the existing lock AND interacts correctly with the bolt work.

Install and correctly align the new lock, tighten the mounting screws and set a new combination and test it several times before closing and locking the door for the first time.

NOTE:   I never recommend lock disassembly as a DIY project for the same reason that I never recommend using locksmiths for safe work.    Lack of training, knowledge and/or tools can result in a very expensive lockout.

I recommend you contact a local safe company to have their safe technician service, inspect and reset your Mosler lock to ensure proper operation - and/or have them replace the lock.

Options include sticking with a mechanical lock or upgrading to a digital lock.  

Hope this helps,

---------- FOLLOW-UP ----------

QUESTION: do you have any info on the big red brand of replacement locks??  i am still nervous about the electronic digitals, should i be??

i did the rating thing for you, outstanding, you gave me the confidence i needed. big thanks!

Hi Gary,

The Sargent & Greenleaf mechanical locks are probably the best mechanical locks around - HOWEVER, that being said - in general, people are more worried about cost than quality.

What was it that Ben Franklin said:   "The bitterness of poor quality remains long after the sweetness of low price is forgotten"!

You can check out Big Red safe locks web page by going to:

Big Red has a video on their web page of their standard Group 2 lock, dialing over 70,000 consecutive openings before having a failure.

NOTE 1:   Pretty much ALL of the manufacturers consider their locks to have a THREE year life under normal commercial, daily usage!

Note 2:  While I understand the manufacturer's use of "plastic parts" inside of safe locks for purposes of radiological surreptious access to the safe, I don't condone ANY manufacturer's making cheap locks simply to increase profit margins.   Again, however I do understand why they are doing it.   They have been forced to cheapen their products because of consumers who refuse to pay for quality.    That being said, there is not a manufacturer on the planet who isn't willing to sacrifice quality to reduce the price.

Bottom line, unless you are going to buy a quality lock, like S&G's 6500 series vault lock, you are going to get pretty much the same quality from all the manufacturers.   Doesn't really matter which one.

As far as Digital locks go, the same info above holds true for digital locks.   Because digital locks operate differently than mechanical locks there ARE some good ones and bad ones.   Price isn't necessarily a determining factor of quality in this case though.   While ALL of the digital lock makers each have some quality ideas, many of them simply don't stand up to the test of time and hard usage of commercial use.

All digital locks are subject to side bolt pressure, which will keep the lock from operating correctly.   The question is which ones will recover and continue to operate normally AFTER the pressure is relieved???   The LaGard brand of products were the first to utilize a swingbolt design, held in check by a small solenoid.    This design as been so successful that pretty much all of the other manufacturers have either copied the basic idea or had LaGard manufacture locks to their specifications.   Digital locks which use motors seem to be more susceptible to lock failures, as the motor continues to try to retract the lock bolt even if it is bound up.   

A couple lock manufacturer's have attempted to marry the reliability of a mechanical lock with the ease of use of a digital lock.   The only one that has been relatively successful is LaGard.   Their redundant lock gives you the capability of opening the lock using a digital key pad, and worse case if you have an electronic failure, you have the mechanical lock as a back up.
This in no way means that LaGard's redundant lock doesn't have its own set of problems, it does.   What it DOES mean is that your chance of being locked out of the safe is much less than having ONLY a mechanical lock or ONLY a digital lock.

Digital locks also give you a lot of features that you CANNOT get in a mechanical lock with out spending LOTS OF MONEY for extra equipment.    You can have multiple users, time locks, time delays, TRUE dual custody, audit trails and hook ups to alarm systems or camera monitors.   One lock manufacturer also has a lock which can be hooked up over a LAN or WAN network, so that a customers Loss Prevention department can manage safe locks at multiple remote locations, WITHOUT having to physically be present.

Just like with ANY other item that you purchase, I would expect you to become educated so that YOU can make an informed decision.   I would recommend that you contact your local safe company - NOT a locksmith company - to discuss options and to see examples of various locks.

Hope this helps some what.


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Terry V. Andreasen (Andy)


Safe and Vault related Questions; Antique Safe Repair and Restoration; With over 42 years in the Safe & Vault industry, if I can't answer your question I know where to get the answer. Current Project: Restoration of an Ely Norris Cannonball Safe from the early 1900's. Will answer Safe & Vault related questions concerning age, value, restoration, moving, opening & repairing, parts, operation and history. Note: It is not my intention to teach you to open safes or to provide information which may aid in the unlawful opening of a safe. I will not give out drill points or information which I deem inappropriate.


44 years in the Safe & Vault Industry. Owner and Service Manager for one of the largest Safe & Vault companies on the West Coast. Graduate of Lockmasters Safe Lock Servicing, Safe lock Manipulation and Safe Deposit Lock Courses. Graduate of Locksmith Institute. Certified Instructor for the California Locksmith Association teaching Basic and Advanced Lock Servicing, Basic Safe opening and Repairing. Factory Trained by AMSEC, LORD Safes, LeFebure, Mosler, KabaMas, LaGard and Sargent & Greenleaf Author of "The Coffee Table Guide to Antique Safes".

SafeCrackers International and the National Antique Safe Association Safe & Vault Technicians Association (SAVTA)

The Coffee Table Guide to Antique Safes

Graduate of Locksmith Institute 1972 Graduate Lockmasters Safe Lock Servicing 1974 Graduate Lockmasters Safe Lock Manipulation 1975 Graduate Lockmasters Safe Deposit Lock Servicing 1985 Instructor Certified - California Locksmith Association - 1985 Factory trained by AMSEC, MAJOR, STAR, Johnson-Pacific, Kaba-MAS, Allied-Gary, ISM, Lord, Brown Safe, EXL, Mosler, Diebold.

Awards and Honors
2009 - 2015 - Listed in AllExperts Top 50 Experts. All Expert Categories - Safes & Security Containers, Locksmithing, Antique Safes. Retired US Army Chief Warrant Officer (CW4), with 39 years of total service. With numerous awards from Vietnam, Desert Storm and Operation Iraqi Freedom. US Navy - 1971-1981 US Army Reserve 1984-2013 US Army Retired

Past/Present Clients
US Secret Service, FBI, BATF, Local Law enforcment agencies, Diebold, Hamilton Pacific, Red Hawk Int., Chubb International, Bank of America, Wells Fargo Bank, Mechanics Bank, El Dorado Savings Bank, many Credit unions and smaller banks. McDonalds, Togos, BurgerKing, TacoBell, Carls Jr. FoodMaxx, SaveMart, Lucky's, Albertson's, Raley's, Safeway, NobHill, Bell Markets, PW Markets. Great America, Century Theatres, Cinemark Theatres, UA Cinemas, and many homeowners and small businesses. Provide warranty service for lock and safe manufactures. Service Area is Northern California (Fresno to Oregon and Western Nevada)

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