Jaeger-LeCoultre Memovox cal 916 - any tips? "do not open" barrel.

[Knebo]

Hello everyone, 

I recently acquired a watch that I've long considered a "grail". A JLC Memovox. Specifically, the reference E875 ("Speed Beat") with a calibre 916. I got it for really good price and it is in full original condition. 

It's still running quite well, but I do want to service it. 

I found the service manual online (attached) and it seems to be doable. JLC 916.pdf

But I'd still be grateful for any tips!! 

One specific question I have is related to the mainspring barrel. The manual says that the barrel "should never be opened. In case of defect, replace the whole barrel assembly". 

Now, I've opened "do not open"-barrels before and reused them with no problems. And there are other threads discussing this matter in a more general way. But I'd be very grateful if anyone had specific knowledge of this movement or other JLC movements from the 1970s. 

Obviously, it's impossible to source a NOS barrel complete for this movement (and even if, the breaking grease and arbor lubrication would not be in good condition anymore). 

So I'm left with only two options: open the barrel as usual or just leave it closed and reuse. (Well, or I pay 4-digit service costs at JLC/Richmond group.)

 

[nevenbekriev]

I don't know for this specific calibre, but sometimes this kind of barrels can not be opened, as the lid is sealed by rolling  material of the barrel over it. So, if the barrel is openable, then open it and go ahead. If doesn't seems to be openable, then show pictures here to think on.

[mikepilk]

Cousins show the complete barrel as discontinued, but they do show a mainspring. Doesn't say if it's the alarm spring, but I wouldn't expect the alarm spring would be an automatic?

[Knebo]

Thanks @nevenbekriev 

Thanks @mikepilk. I've already bought that original JLC mainspring from Cousins. It is indeed the actual mainspring (not for the alarm). I ordered it before noticing the "do not open" issue.

 

[nickelsilver]

The JLC sealed barrels I've dealt with are sealed, with the lip burnished over like Nevenbekriev says. They can be opened, but you have to push the lip more open to get the lid to seat again correctly and it's still a bit hairy. They aren't as bad as Zodiac (those you can forget about opening much less closing without issue).

 

The chances of mucking it up are high enough that it's probably safest just to add a little lubricant at the arbor and call it good.

[mikepilk]

Having sealed barrels like this must effect the value of some of these movements, if the mainspring cannot be changed.

If you search on ebay  @Knebo for "Jaeger LeCoultre cal 916 barrel", there are a couple of barrels for sale, but not cheap though. 

 

Edited May 30 by mikepilk

[Knebo]

33 minutes ago, mikepilk said:

If you search on ebay  @Knebo for "Jaeger LeCoultre cal 916 barrel", there are a couple of barrels for sale, but not cheap though. 

You are right. Very few though, and only one in Europe...for 180 EUR. 

But I'm not sure how useful it would be to get a 40-50 year old barrel complete. Even if NOS, wouldn't the contained (probably non-synthetic) lubricants be useless by now? 

1 hour ago, nickelsilver said:

but you have to push the lip more open to get the lid to seat again correctly and it's still a bit hairy.

Could you elaborate on this? I can't quite picture what you mean. 

 

1 hour ago, nickelsilver said:

probably safest just to add a little lubricant at the arbor and call it good

This raises an interesting question that I've sometimes wondered about in other situations. If I'm not sure which lubricant was used before, and I'm using what I think is right nowadays (e.g. HP 1300 in this case) - what are the implications/risks of effectively mixing different lubricants, especially if old/natural and new/synthetic?

[nickelsilver]

48 minutes ago, Knebo said:

You are right. Very few though, and only one in Europe...for 180 EUR. 

But I'm not sure how useful it would be to get a 40-50 year old barrel complete. Even if NOS, wouldn't the contained (probably non-synthetic) lubricants be useless by now? 

Could you elaborate on this? I can't quite picture what you mean. 

 

This raises an interesting question that I've sometimes wondered about in other situations. If I'm not sure which lubricant was used before, and I'm using what I think is right nowadays (e.g. HP 1300 in this case) - what are the implications/risks of effectively mixing different lubricants, especially if old/natural and new/synthetic?

I use a 3mm carbide rod with a crisp flat face (steel is fine too), and, holding the barrel vertically, under the microscope, teeth resting on a hockey puck, I carefully slide the rod along the part of the barrel that clips to the lid, pressing quite hard to deform the metal back out. If you don't do this, when you go to press the lid on it will catch, causing damage to the lid and barrel, often with no feasible repair. It's actually ok to tilt the rod a little after getting the lip straightened, to form a slight bevel around the perimeter to facilitate the lid going back in.

 

It's not a fun job to do.

 

As for mixing lubricants- that can be a real issue. One would imagine that given its age it was probably lubricated with non-synthetic, so probably best to use D5 or similar rather than an HP oil. I don't know specifically which lubricants aren't compatible or what the real results of mixing those are, but D5 is a pretty safe bet.

[Knebo]

41 minutes ago, nickelsilver said:

I use a 3mm carbide rod with a crisp flat face (steel is fine too), and, holding the barrel vertically, under the microscope, teeth resting on a hockey puck, I carefully slide the rod along the part of the barrel that clips to the lid, pressing quite hard to deform the metal back out. If you don't do this, when you go to press the lid on it will catch, causing damage to the lid and barrel, often with no feasible repair. It's actually ok to tilt the rod a little after getting the lip straightened, to form a slight bevel around the perimeter to facilitate the lid going back in.

Thanks for taking the time to describe this. 

I this what how I should imagine it? 

[nickelsilver]

Swing the rod 90 degrees, it's the side that does the work. If you have a lathe you can grab the barrel in a wheel chuck and hold the bar in the slide rest, turn the headstock by hand while applying pressure- much less awkward than holding the barrel by hand.

[Knebo]

OK, I see. I get the point.

Thank you!

Do you also try to "close the lip" again afterwards? Running the rod around the closed barrel from the other side? 

[oldhippy]

Gone are the days where you could just replace the whole unit. If there is nothing wrong with the complete unit I would just clean it and a tiny drop of oil each side of the arbor. If you open it you could distort the cap and it will never fit proper again normally the cap is thin. My advice is do not open.   

[Knebo]

Alright!!

My big project has started. I'll start a walkthrough thread about it soon.

 

But about the barrel. Here are some pics from my microscope. Can you tell from it if it's ok to open (and close again)? To my, frankly, it looks like it can.

[Jon]

I would always open a barrel, regardless of what is written on it. The idea of leaving a mainspring inside a skanky old barrel with old grease or maybe a break or two and not no it doesn't sit with me. It's like Schrödinger’s Cat. Is it alive or dead or both based on quantum indeterminacy. Same goes for the mainspring, rather than the cat, so to speak. You will never know until the barrel is opened.

My old Master always told us never to remove the crown wheel! WTH! and this was someone with decades experience. As they say, 'Take what is good and leave the rest behind'. That one got left behind very early on!

@nickelsilver gave an excellent explanation how to manipulate the barrel with rod once opened to facilitate closing it again without damage. 

[Knebo]

Thank you @Jon and @nickelsilver again.

I took the plunge and opened it.

It came off with no problems at all. However, upon close inspection, I could see the "lip"/burnishing. So I followed @nickelsilver's advice and tried to gently bend the metal back out. I used a bracelet tool for it... and quite frankly, I'm very happy with the result.

I tested my success by reinstalling the lid. Went back in smoothly. And off again.

I guess when I install the new mainspring and the lid, I'll try to burnish the edge of the barrel back towards the lid.

 

Pictures below:

1. Before (took of barlow lens for even better magnification)

2. Opening the usual way was no problem. Not crazy dirty, but for sure wouldn't have been a good idea to just re-use. The breaking grease was had turned into more of a powder.

3. This is what I used. The pointy end of a bracelet tool.

4. Here you can see the flattened-out lip up until the notch (included). Then the still burnished inwards lip below that.

5. After two-three rounds, I'm satisfied.

6. After closing the barrel again, you can see more space between lip and barrel edge (if you compare to picture 1). The lid installed with no problems. Not perfectly pretty, I'll admit. But hopefully it'll look ok and be fully functional (secured/closed) when I burnish it back after installing the mainspring.

 

 

[Jon]

Nice one! Anything outside our experience is always going to be nervy, but you've more than likely helped a lot more who have encountered this 'Do not open' barrel malarkey by showing the great photos you've taken and @nickelsilverexplanation.

[Knebo]

Thanks @Jon for the kind words.

Indeed, for the others out there: not much force is required to flatten out the burnishing. However, you need a steady hand and a good view on it. I cannot imagine doing it without my stereo microscope..

 

[nickelsilver]

Nice work Knebo, that looks great!

 

Just a note (I'm sure I've mentioned it before but anyway)- of the barrels marked as sealed, the one I've encountered  that's really really sealed is Zodiac. The burnishing is so tight the lid deforms to be point of being useless, requiring making a new one, at least in my experience. And I just got one in... haven't looked inside, hoping it not actually a Zodiac movement .

[Knebo]

Oh, @nickelsilver, have I asked you before where you are located? I'm also in Switzerland --  in Geneva.

[nickelsilver]

I'm in Neuchatel- before that Nyon, before that Ste-Croix, before that Ohio .

[RichardHarris123]

I don't think anyone has asked yet but why? A sealed barrel seems to make no sense at all. 

[eccentric59]

32 minutes ago, RichardHarris123 said:

A sealed barrel seems to make no sense at all. 

A new mainspring £10, a new barrel complete £100. Any questions?

[Knebo]

1 hour ago, nickelsilver said:

I'm in Neuchatel- before that Nyon, before that Ste-Croix, before that Ohio .

Ah, just a bit too far for a spontaneous meet-up. But please let me know if you're ever in Geneva! 

[nickelsilver]

2 hours ago, Knebo said:

Ah, just a bit too far for a spontaneous meet-up. But please let me know if you're ever in Geneva! 

Haha yes!

[canthus]

On 5/30/2024 at 1:24 PM, Knebo said:

This raises an interesting question that I've sometimes wondered about in other situations. If I'm not sure which lubricant was used before, and I'm using what I think is right nowadays (e.g. HP 1300 in this case) - what are the implications/risks of effectively mixing different lubricants, especially if old/natural and new/synthetic?

Re mixing oils.  It would be ok to mix normal mineral oils (D5) with modern synthetic oils that are of the PAO type (HP1300 etc).  PAO oils are basically synthesised from mineral oils and as such have all the undesirable properties of basic mineral oils removed or greatly reduced.  'Synthetic' lubricants can also be chemicals not related to mineral oils at all, hence my 'synthesised'  usage for PAO oils.  If you use a semi-synthetic motor engine oil in your car/truck, this is in fact a mixture of mineral and PAO.

Greases are another matter though, as they are a mixture of an 'oil' and a 'soap', and it is more likely that the reactions of the soaps that can cause problems.