Jaeger LeCoultre calibre 916, Memovox

[Knebo]

Hello everyone,

this will be my first proper walkthrough and also my most complicated watch yet. A beautiful JLC Memovox E875 ("Speed beat") with calibre 916.

This is the first of several posts: disassembly. You'll see my order of disassembly and close-ups of all the screws. Those are the main points. If there's anything particular, I'll write a comment. Otherwise the pictures are hopefully self-explanatory.

 

Here's the beauty before disassembly:

 

Ready to go with nicely dressed tweezers... also, screw slots are generally very thin so I also dressed all screwdrivers to very fine tips.

 

 

 

inside of the caseback has a little knob that is hit by a hammer to create the alarm sound.

Movement complete.

before any disassembly, you can already see the magic level system of the automatic works

I start by taking off the rotor.

rotor underside

rest of automatic works with three blued screws.

magic lever system

balance first..

identical stems. 

 

two case screws

 

 

retention ring holds the gasket

 

hands off and some dial-porn

 

dial feet screws are nicely positioned so you can hold the movement in one position and access both at the same time. Thanks, JLC!

 

both dials off

 

let power down before this point!

 

driving wheel for ratchet wheel / kinda-reversing wheel

 

the alarm system

 

 

 

train bridge

 

I take the opportunity to remove the clutch wheelS and sliding pinionS. Again, both are identical. Nice.

 

back to the train

barrel can come out without damaging the center wheel. But careful. 

underside of the bridge with TWO crown wheels. NOTE: one "seat" is missing. Its absence has cause some damage to the bridge. I had indeed felt some resistance when winding the alarm barrel and it was one reason why I wanted to service it.. Part 414 is ordered from eBay. 

 

 

Barrel says "do not open". A whole other thread is devoted to this, see here:  

 

 

 

let's do the dial side:

 

this spring was hard to get out. only an oiler would squeeze under it.

the date wheel can stay assembled like this (no disassembly shown in the manual)

previous watchmaker liked oil a lot.

the alarm activation wheels

lots of wheels..

 

also part of the alarm system

 

pretty cool how the two keyless works are kind of the same and with some overarching parts

damn, this spring was hard to get out.

canon pinon and then the center wheel

i remove balance jewels on both sides for thorough cleaning and reinstall the balance for cleaning.

 

 

 

 

 

 

 

alarm barrel is normal (no "do not open").

 

the main barrel takes some nerves to open, but does so just fine. However, the edge of the barrel (where it holds the lid) is burnished a bit. I'm smoothing it out with the pointy end of a bracelet tool. This will allow the lid to go back in without problems. I'm planning on burnishing it over again when the new mainspring is installed.

work in progres.

done

 

 

Edited June 15, 2024 by Knebo
Removed random pic at the end of the post

[nevenbekriev]

Just in case You didn't notice this:

The jewej is broken and no wonder, the decision of the movement designer is a little strange here.

[Knebo]

32 minutes ago, nevenbekriev said:

Just in case You didn't notice this:

The jewej is broken and no wonder, the decision of the movement designer is a little strange here.

Hi @nevenbekriev, thanks for having such a close look. 

But it's actually all how it's supposed to be. It may be an optical illusion. These a 2/3 circle brass bushing on the lever itself and a full jewel on the plate below. 

The pic from the manual will clarify:

[VWatchie]

Thanks for your walkthrough @Knebo  and what a stunning watch!

This is my second time seeing the pawl lever system in a non-Japanese movement. Judging by Kalle Slaap's reaction in this video I thought the only exception was the Panerai P.9000.

When you also consider that several other parts of the movement look Japanese, you suspect that Panerai's movement may have been commissioned by Seiko but marketed as Swiss, or Panerai may have simply acquired Japanese watchmakers.

Anyway, having researched it a bit more I just learned that the magic lever system was invented by Seiko in 1959 and that several other Swiss movements are using it. I also learned that the JLC 916 was introduced in 1969.

About the "broken jewel". I also noticed it looked a bit funny and judging by its colour in the picture I too thought it was a jewel and not a brass bushing. Thanks for clarifying!

[RichardHarris123]

Kalle also does the video where he explains what Swiss made " really means.

[nevenbekriev]

Sorry, I didn't realize this is a bronze bearing.

[Knebo]

Hello, 

I'll do the cleaning and some assembly today. Hopefully, I'll upload some pics later today. 

I have two questions:

1. lubrication of the "driving gear assembly for ratchet wheel" 

The manual only prescribes lubricating the clicks and the pinion with grease (and the pivots of course):

But this guy also lubricates another point (https://youtu.be/LmHqj5RMXqk?si=Mg5D7U0DEt_xf_MK) 

 

What do you think? 

 

2. Cleaning and lubrication of rotor ball bearings. From the service guide:

a. Would you follow this cleaning approach instead of my usual L&R No111 (ammoniates watch cleaning solution) and L&R No3 (watch rinsing solution, two cycles)? 

b. Would you use Moebius 941 for the balls?? First time I see this in a manual? Normally, I'd either use 9010 or Lubeta V106. What do you think? 

[Knebo]

A few thoughts on my own question 2b.

9010 vs 941:

The two are quite similar if you look at the tech sheets (and look past the spider charts). What I find weird is that the spider chart seems to indicate higher viscosity for 941, but the actual numbers are higher for 9010 at all temperatures. 

From this info, I feel like going for 9010.

However... why does JLC recommend 941 if 9010 already existed and was even used elsewhere in the movement?? 

[Knebo]

Alright... while I still hope for some answers, I'll continue my walk-through. 

For now, just a quick post about the cleaning procedure. I did peg all the jewels and cleaned off dirt, oil etc with Rodico. Pivots cleaned with EVE pin polishers (only briefly to remove dirt).

Then parts go in a couple of cleaning baskets (round brass ones) and inside of stainless tea filters... inside the Elma waterless cleaning (one 10min cycle) and rinsing liquids (two 10min cycles) in the ultrasonic.

 

After the cleaning, I put the parts in storage trays, cover them with a type of cellulose "paper" (that lets through the air, but protects from dust). And put that in the oven at 57°C (not too hot to avoid melting the shellac on the roller jewel).

Edited June 18, 2024 by Knebo

[VWatchie]

I follow your walkthrough with great interest! 

On 6/17/2024 at 7:12 AM, Knebo said:

a. Would you follow this cleaning approach instead of my usual L&R No111 (ammoniates watch cleaning solution) and L&R No3 (watch rinsing solution, two cycles)?

I'm not sure how I would do it but still think I would try to follow their recommendation. My only question is how do you practically go about quickly rotating the rotor in the benzine?

On 6/17/2024 at 7:12 AM, Knebo said:

b. Would you use Moebius 941 for the balls?? First time I see this in a manual? Normally, I'd either use 9010 or Lubeta V106. What do you think?

I would follow their recommendation. Oiling correctly is often an underrated art with far greater consequences than most people realise. I don't think it's a coincidence that JLC recommends 941. That said, in this particular case, I think you can safely use 9010 if you don't have or don't want to invest in 941.

11 hours ago, Knebo said:

What I find weird is that the spider chart seems to indicate higher viscosity for 941, but the actual numbers are higher for 9010 at all temperatures.

Yes, it is undeniably strange. Maybe the explanation is that there is a difference between viscosity and "viscosity index"!?

11 hours ago, Knebo said:

However... why does JLC recommend 941 if 9010 already existed and was even used elsewhere in the movement??

I understand that 9010 is a much older oil than 941. I guess JLC has found through practical experiments that they get marginally better results with 941 for just the rotor bearing, but who knows?

Edited June 18, 2024 by VWatchie

[Knebo]

12 minutes ago, VWatchie said:

I'm not sure how I would do it but still think I would try to follow their recommendation. My only question is how do you practically go about quickly rotating the rotor in the benzine?

I'll give it a try an let you know 

 

13 minutes ago, VWatchie said:

 

On 6/17/2024 at 7:12 AM, Knebo said:

b. Would you use Moebius 941 for the balls?? First time I see this in a manual? Normally, I'd either use 9010 or Lubeta V106. What do you think?

I would follow their recommendation. Oiling correctly is often an underrated art with far greater consequences than most people realise. I don't think it's a coincidence that JLC recommends 941. That said, in this particular case, I think you can safely use 9010 if you don't have or don't want to invest in 941.

I've accumulated quite a few lubricants for that reason... but in this particular case I'm a bit hesitant. 

 

13 minutes ago, VWatchie said:

 

11 hours ago, Knebo said:

However... why does JLC recommend 941 if 9010 already existed and was even used elsewhere in the movement??

I understand that 9010 is a much older oil than 941. I guess JLC has found through practical experiments that they get marginally better results with 941 for just the rotor bearing, but who knows?

Yea, I really wonder.

What's interesting, is that for calibre 918 (introduced in 1994), which seems to have the same rotor construction as the 916 (introduced in 1969), JLC recommends "immersing [the oscillating weight] in a mixture of benzine and 0.02% D5 oil" (is that basically what Lubeta V106 is??). So they didn't stick to 941..

 

 

[Knebo]

After cleaning, here's my usual "movement art" picture. 

Assembly coming later..

 

 

Edited June 18, 2024 by Knebo

[VWatchie]

I forgot to mention and you may already know this but whatever oil you use for the ball bearing, you should apply a minimal amount. Otherwise, you risk inhibiting its free movement.

[Knebo]

11 hours ago, VWatchie said:

I forgot to mention and you may already know this but whatever oil you use for the ball bearing, you should apply a minimal amount. Otherwise, you risk inhibiting its free movement.

Thanks @VWatchie. Yes, I know.

Now I am wondering if I should go with 9010 or a bath in Lubeta V106 (I have it and never used it...).

 

Edited June 19, 2024 by Knebo

[Knebo]

Hello all!

Now I finally made time to upload these endless pictures of my assembly.

First, a few DISCLAIMER:

- while I took photos of a lot of the oiling points, I didn't capture all of it. I lubricated every point indicated in the manual, which is available here: https://watchguy.co.uk/tmp/JLC 916.pdf

- oils/greases used: 9010 (as indicated in the manual), HP1300 (where 8141 is indicated in the manual), 9415 (where 941 is indicated in the manual; except for the rotor ball bearing where I also used 9010), 9405 grease (where manual indicates PML Hamilton), and 8217 as breaking grease for the mainspring barrel wall.

- IMPORTANT: as I started assembly while I was still waiting for a spare part for the train bridge (a crown wheel seat), I didn't follow the order of assembly that was recommended in the manual (which suggests assembling the train first). I'm just showing how I did it (and how it also worked just fine). 

 

1. Prep work:

1a. Epilame of pallet stones and escape wheel (and cleaning its pivots afterwards):

using my trusty syringe to apply Fixodrop only on the pallet stones and not the pivots.

cleaning Epliame off the pivots

 

1b. Alarm barrel

standard non-automatic barrel/mainspring for the alarm.

 

1c. Mainspring barrel

I apply breaking grease next to the notches...

...and spread it out...

...so that no grease protrudes from the barrel wall...

... when I push in the new mainspring (NOS JLC original)

 

 

the edge of the barrel wall is burnished back towards the lid, as it was before

work in progress, but obviously done all around

 

2. Keyless works (first half)

lubricating hole for setting leverS

both setting levers installed, posts for both yokes lubricated and installed. Contact points between them lubricated. The the spring.

contact points lubricated

lubricating two posts

wheels on

NOTE: mistake here! The setting lever spring plate should not be screwed in at this point. The minute work cock/plate should be installed first and the two screws hold both plates!

No issues caused by this, though.

 

3. Centre wheel

before installing canon pinion and minute wheel on the dial side, I go to the train side for the centre wheel. 

lubrication first.

center wheel cock 

 

the barrel and ratchet wheel are unusual in that there is a "ratchet wheel cap" which rotates in the train bridge bearing, not the actual barrel arbor.

I found that screwing on the cap needed too much force (and I was afraid of pushing out the brass bearing in the mainplate), so I removed the whole assembly and screwed in the cap on a bench block.

The whole assemble then slides onto the mainplate and around the center wheel (if you are a bit careful).

I should normally assemble the whole train at this stage, but since I was still waiting for part (seat for crown wheel) for the train bridge, I am proceeding with whatever else I can assemble. To keep things in place, I will still put on the train bridge, but without crown wheels and gear wheels.

However, I put in the third wheel at this stage, because the mainplate jewel hole is under the dial-side minute wheel. Putting the wheel now will allow me to lubricate it and and to continue the assembly of the dial side.

 

4. Alarm system (train side)

But first I do the alarm system on the train side. Screws are shouldered and are lubricated accordingly.

the U-shape at the tip of this lever is greased...

..and is then engaged with the (dial side) yoke of the alarm winding mechanism.

 

the contact point between the levers is also greased

the star wheel for the alarm hammer

the alarm hammer is greased at the "thorn" which engages with the alarm star wheel.

almost all in place

now the alarm barrel

and the alarm ratchet wheel

now to the alarm bridge. There's another seated intermediate crown wheel (with a reverse-threaded screw!).

all in place

 

5. Keyless works (part 2):

back to the dial side. and now (as indicated a bit before), I can lubricate the dial side jewel of the third wheel...

before continuing with lubricating the posts for the wheels and the center wheel for the canon pinion. 

and putting them in place.

as mentioned before, the double-setting-lever spring plate should not have been screwed in before. I remove the screws and put the minute work plate on and use the same screws to secure BOTH plates.

it take advantage of this moment and also put in place the lower balance jewels. NOTE: I don't use Epilame on these as I've heard rumours that Rolex recommends not to do that to avoid wear from the residue. Also, the service guide explicitly mentions "stop oil" for palate fork and escape wheel, but not balance jewels. 

 

still on the dial side, I now turn to the alarm disconnector, which is lubricated in four places

the disconnector is held in place by a spring.

the alarm coupling yoke and the wheels, particularly the alarm setting connection wheel are a bit fiddle to lubricate and position when putting down the cover plate.

 

the three notches of the special hour wheel are greased on top

NOTE that I've remove the screw from the spring holding down the disconnector. This makes it a lot easier to fit the plate. (if not, the unlocking wheel on top of the hour wheel will keep pushing up, making it difficult to position the plate.

note the little grease dots on the unlocking wheel where it slides on the plate (there was evidence of wear).

now I can secure the spring for the disconnector again.

 

over to the date jumper and jumper spring

contact point greased

oil on the post of the date wheel

date wheel screwed in and date ring positioned.

cover plate secured

 

greasing some of the notches (is that the word?) of the disc

 

6. Back to the train!!

by now, I've received the missing seat for the crown wheel and I take of the train bridge again (leaving the third wheel in its pivot because I already lubricated it from the dial side).

the click is still in place (no need to remove for cleaning)

the seatS get a bit of oil on the outer edges

the the crown wheel

lubricating..

putting the core and screwing in

all that times two.

the service guide only indicates lubricating this part of the seconds wheel (apart from the top pivot in its jewel hole). I do NOT see a recommendation of lubricating the other thick part that goes into the centre wheel... and I didn't lubricate there. But I'm having second thoughts about that... any opinions?

all train wheel in place

 

fitting train bridge: NOTE: remember that the click for the mainspring barrel as well as two "crown" wheels on the underside of the bridge also need to engage. So don't force anything down when it looks like the trains wheels are in their pivots but the bridge isn't going down.

 

after the train bridge, there's another intermediate crown wheel to install (through a hole in the bridge).

 

now the "driving gear for ratchet assembly". these special shark teeth will engage with the magic lever of the automatic works.

The service guide indicates that 

 

 

forgot a picture of the bridge for the driving wheel, but it's visible below.

 

[oiling train jewels]

positioning the pallet fork

and its bridge.

putting the balance. And it ticks!

I let it run without lubrication on the pallet jewels to scrape of a channel of the epilame. Then I remove the balance again and lubricate the pallet exit jewel 4 times.

 

7. automatic works - magic lever!

"magic" wheel inserted to plate and lubricated

magic lever in place. jewel lubrication.

funny two-thirds bearing..

now careful! Place the auto works on the movement and move the "magic wheel" (with the three holes) until the magic levers have properly engaged with the driving wheel. Only when sure about that, screw down the plate.

lubricating the magic lever and some shark teeth of the driving wheel.

I can't upload a video, but I find the operation of the magic lever truly magical!!! 

 

8. synchronizing alarm disc, hands and calendar..

now the most annoying part of the movement! synchronizing the alarm, hands and the date jump....

a. first, you're supposed to put alarm disc and dial into place without screwing it in.

b. then pull out the movement stem and rotate anti-clockwise (as if setting time backwards). At some point, the alarm indicator will "catch" and move anti-clockwise and indicate the correct position of the hour hand. So far, that's easy.

c. but now synchronizing with the data change is tough. The manual says to set the alarm indicator (and implicitly the hands) to 12/midnight.

d. and then take of the dial and date disc, partly unscrew the date wheel and reposition it manually in such a way that it's at the tipping point of clicking to the next date.... Then install the hour hand and test the date change and the alarm function (hand to match up with alarm indicator).

Below is my best attempt at doing so (see that the date jumper is right on the tip). BUT, this is still 20-30min from the actual date change... in other words, it the date changed at 0.20h.

So I kept going back and forth (setting the time/alarm indicator to 23.30 instead of 24h... and trying again). I managed to get it to 10min before midnight. But that was after about 2 hours of trying. I called it a day.

looks promising: "invisible" hour hand and alarm indicator aligned at midnight and date about to change...

...but after installing the hour hand, it see that the actual date change occurs too late

so uninstall, repeat... 

 

when half-happy, I install all hands

nice and parallel

 

I'm not sure the watch was designed with crown gaskets (at least I didn't see any when I disassembled). But I buy fitting ones with the thinnest available thickness (0.3mm, flat). The go in nicely and the crowns/stems still go in fully. I may have improved the water resistance rating of the original watch  On that note, these watches seem to have water damage very often. Finding reference E875 without water damage is not so easy.

 

Now for the rotor...

The manual asks for a particular cleaning procedure:

I wasn't sure if it's necessary because my cleaning procedure already cleaned it in the ultrasonic and with ammonia liquids.

So I did a test. My three cleaning liquids lined up (from left to right): Elma Suprol Pro RINSE (i.e. the last liquid in my cleaning cycle), washing benzine, Essence of Renata.

All applied to a my wife's makeup mirror (don't tell her!!!).

To my surprise, the cheapest of the liquids (the washing benzine) leaves the least residual. Essence of Renata, shockingly, the most.

I don't have a fitting brass shaft laying around, so I use pegwood (which I previously left in in washing benzine for a while, to eliminate the risk of contaminating the benzine for the rotor).

You don't actually have to spin the rotor itself. When rotating the pegwood, the ball bearing turns and the rotor stands still. I do that for a minute or so and dry it quickly afterwards.

I then lubricated the balls with 9010 (after some debate with myself because the manual says 941, which I don't have). But 9010 seems to oil of choice for most modern ETA movements, so I guess it'll do fine.

screwing in the rotor now.

 

DONE!

Last thing!

The regulator is a bit unusual...

The method of regulating is the same as always, though. BUT I ran into some confusion.. I managed to regulate it pretty much to 0sec/day (and 0.0 beat error). But when I can back an hour later, the watch somehow ran at minus 30sec/day... very bizarre. I repeated the regulation. Same phenomenon an hour later...

My theory: since the "buckle" is in permanent contact, there may be a bit for friction between it and the hairspring. So, when moving the regulators "buckle", it may pull the hairspring along just a bit. Thus, "pretending" to be regulated to a certain rate.

But as the hairspring oscillates for an hour or so, it gradually moves to the actual permanent position of the regulator buckle. In this process it moves from 0sec/day to -30sec/day. 

Consequently, I intentionally regulated the watch to +30 sec/day. And waited an hour.

And yes, what a pleasant surprise, it ends up pretty much dead-on. 

I can't say for sure that my theory is correct, but at least I know that there's nothing really wrong with the regulator.

 

Testing results:

power reserve 46h (online I find 40, 44h or 45h for this movement. The manual, strangely, doesn't indicate any)

test of winding efficiency: from dead, wearing for 8h in moderately active use (mostly office, but a few walks and some driving): watch is fully wound.

Peak amplitude straight from the wrist: 294°

Rates and amplitudes at full wind (+1h) and after 24h.

Dial up: -6@275° ; -1@244°

Dial down: +1@274° ; +5@240°

Crown(s) down: 0@260° ; 0@222°

Crown(s) left: +4@255° ; +6@223°

Crown(s) up: +3@249° ; +6@225°

[Crown(s) right: -3@252° ; -1@225°]

Beat error: between 0.0 and 0.1ms.

 

 

And here is the final product (also with a new crystal)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Edited June 24, 2024 by Knebo

[Knebo]

A quick follow up on one question I included in last night's post. About the lubrication of the seconds wheel. 

As indicated in the manual, I only lubricated the thicker point indicated by the green arrow. NOT the one with the orange arrow (also thicker part, closer to the pinion/wheel. But should I have?

After some thinking, I believe/hope that the extended seconds pivot only touches the inside of the center wheel where I indicated it with the blue circle (bottom of the picture). If that's true, it makes sense to only lubricate the specific point with the green arrow.

This guy, however, also lubricates the upper part (orange arrow): https://youtu.be/LmHqj5RMXqk?si=G79SyuxK0-5fHHYL&t=1163

 

[rossjackson01]

Knebo

What an excellent and enjoyable post.

Thank you