WWT Shows CLICK TO: Join and Support Internet Horology Club 185™ IHC185™ Forums

• Check Out Our... •
• TWO Book Offer! •
Go
New Topic
Find-Or-Search
Notify
Tools
Reply to Post
  
What's this all about (Subject: 4992B 24 & 12 hour) "Click" to Login or Register 
IHC Life Member
Picture of David Abbe
posted
To compare the 4992B 24 and 12 hour . . .

 
Posts: 6518 | Location: Southern California in the USA | Registered: July 19, 2007
IHC Life Member
Picture of David Abbe
posted
The 24 Hour is 1945-48 vintage S/N 4C110078, and the 12 hour (conversion Lindell?) is c.a. 1943, S/N 4C69651.

 
Posts: 6518 | Location: Southern California in the USA | Registered: July 19, 2007
IHC Life Member
Picture of David Abbe
posted
The movements look (to our un-trained eyes) to be identical . . .

 
Posts: 6518 | Location: Southern California in the USA | Registered: July 19, 2007
IHC Life Member
Picture of David Abbe
posted
The 4992B 24 Hour watch "Hacks" . . .

 
Posts: 6518 | Location: Southern California in the USA | Registered: July 19, 2007
IHC Life Member
Picture of David Abbe
posted
Now given (that we can all guess or know) the only changes to a 24 hr to make it 12 would be to replace the 2 24 hour hand gears with 12 hour "922" type gears, and put on a 12 hour dial . . . then WHY is the 12 hour "conversion not a "Hacking" watch?

 
Posts: 6518 | Location: Southern California in the USA | Registered: July 19, 2007
posted
Perhaps the hack spring was removed by a watchmaker because it was too much trouble to adjust after cleaning?

Norman
 
Posts: 153 | Location: Northeastern United States | Registered: December 18, 2005
posted
I have just bought a 24 hour and 12 hour 4992B, though as yet only the 12 Hour has arrived. It is very nice, very acurate and is has a hack lever installed, but not working.

I can see the 'stop wire', and some very minor movement of same when the stem is moved. However the hack is not functioning.

Does anyone have any ideas why? I guess there must be some thign wrong in the stem, clutch, lever area.

Tony
 
Posts: 48 | Location: Canberra in Australia | Registered: May 16, 2012
posted
Hi David. In the photo of the backs, I am not seeing any of the standard military markings. Are they just worn down or are they absent. If they are absent it would seem that as part of the later conversion that either the back was ground down to remove them, which is a shame as the markings are so important these days, or the back or entire case are replacements as well.
 
Posts: 854 | Location: Baltimore, Maryland USA | Registered: September 20, 2004
posted
My 12 hour 4992B does not have gov markings on the back and has never had them. My guess is that these were either not made to service government contracts, no US Gov engraving on the movement either, or they were civilianised.

As mentioned above, the hack lever is evident but not working.

Tony

 
Posts: 48 | Location: Canberra in Australia | Registered: May 16, 2012
posted
^

Movement

 
Posts: 48 | Location: Canberra in Australia | Registered: May 16, 2012
posted
^

Hello, this just arrived. It is a really nice Hamilton 4992B.

I posted it here because I thought all 4992B watches were built under military contract, but there is no "US Gov" engraving within. The serial number puts it somewhere near 1942 I think.

The watch is very accurate and the runs well and only has one minor clutch. The Hack function is not working. You can see the hack wire, but it is doing nothing.

This dial looks like a silver metallic type paint. I have no reason to think this is anything but genuine but though out this forum I have yet to see or hear about anything other than a Black or White Dial.

Any information you may be able to provide would be most welcome particularly about the dial and getting the hack function working again.

Tony


Movement Zoom

 
Posts: 48 | Location: Canberra in Australia | Registered: May 16, 2012
posted
^

Case Back

Case Back
 
Posts: 48 | Location: Canberra in Australia | Registered: May 16, 2012
IHC Member 1335
Picture of Tom Brunton
posted
or not inscribed as to uses and disposed of unmarked at wars end Wink
 
Posts: 1754 | Location: Aylmer, Ontario in Canada | Registered: December 15, 2009
IHC President
Life Member
Picture of Lindell V. Riddle
posted

Tony,

(NOTE: We combined several of your posts into this topic to help avoid duplication and confusion.)

Thousands of 4992B watches were converted from 24 to 12 hour after the war, many watchmaking schools had that exercise as part of their curriculum. Your new acquisition, like the one David shared at the beginning of this topic is simply one of those converted movements. The dial on your watch is in harmony with the conversion that we explained to you in a previous topic "Ok, guidance sought on 4992B's" where I provided a link to step-by-step conversion details, for edification I urge everyone interested in these watches to study this carefully...

"Hamilton 4992B 12 to 24 Hour Change Back" by Samie Smith

On the movement markings issue, early 4992B movements had the "U.S. Gov't" markings among others. Later they were dropped and the markings simplified. What you have in number 4C41257 represents the later style. Study of this topic will be helpful in learning more about these interesting watches...

"Evolution Of 4992B and 3992B Markings, Numbers and Database"

So far as the lack of military markings on the case-back, there were some cases that were not marked originally, there were replacement cases and markings can be removed by chucking the back in a lathe and turning it. Just for fun, see if you can verify the numbers on your case-frame, bezel and back.

The hack feature on your watch may be out of adjustment, if you see it and it will move when the crown is pulled upward then it can likely be reset to function correctly. With proper service and adjustment this would be an good carry-watch, you'll never wear it out and one day your grandchildren will fight over it!

Those are my thoughts, let's see what others say!

Lindell

Wink
 
Posts: 10545 | Location: Northeastern Ohio in the USA | Registered: November 19, 2002
posted
Well, my 24 hour watch arrived and as described by the seller the balance staff is US. I have ordered a replacement, though I have also been offered a complete balance. I am uncertain of my ability to replace the staff and poise it with put breaking the balance.

To confirm that this was all that was wrong I swapped the entire balance, including the balance bridge from my 12 hour. Please to report it runs perfectly.

The upside though it that my wife loves and now wants a 24 hour watch of her own. This is some form of affirmation!

Next problem is to find one at a price she/we can afford. Surprising many current sellers on the "bay" site wont ship outside the USA go figure. Anyone have a nice 24 hour 4992B then I have a good home for one.

Cheers, Tony
 
Posts: 48 | Location: Canberra in Australia | Registered: May 16, 2012
  Powered by Social Strata  
 


©2002-2019 Internet Horology Club 185™ - Lindell V. Riddle President - All Rights Reserved Worldwide

Internet Horology Club 185™ is the "Family-Friendly" place for Watch and Clock Collectors