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Seiko 6R15 Service Walk-Through


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This is my first service walk-through, for which I've chosen this well know Seiko movement. It has a lot of similarities and common parts with the 7S and 4R families. The most notable differences are a separate bridge for the auto winding, and a better mainspring giving 50 hours power reserve. Also, the tiny anti-shock for the train wheels (of debatable usefulness) are not present. Some version have a cotes de Geneve finishing, the one pictured does not. Just like the others it is quite easy to work on. Find attached the technical guide for the SII version, which is named NE15B,
 
In this walk-trough my intent is to give practical advice on certain aspects, which comes from my personale experience and reasoning,
Reassembly and lubrication will be covered in the 2nd part. Let's start with the disassembly for which the absolutely indispensable tools are:
  • Movement holder
  • Hand remover  tool
  • 1.4mm and 2.0mm flat head drivers
  • Seiko cross-head driver
  • Fine or medium tip tweezers
First, I recommend to remove rotor weight with the movement stil in the case, as it it of impediment for all the work to be done later.
The movement is kept in case with 2 screws and 2 tabs (not pictured). Remove these, case ring and stem (usual pressing point with crown full in), the movement can now drop from the case - unlike the 7S and 4R where the plastic ring keep it place with some friction.
 
You can now place movement on holder, reinsert stem as it's needed to hold related wheels in place until the very end.
Remove hands with your favorite tool, then keeping movement in hand or placing it on the holder with a plastic protection, quarter-run dial the feet retainers at 3 and 10.
post-1542-0-02442400-1454158215_thumb.jp
 
Gently push the dial out, I recommend to place it in a plastic bag for additional protection. The movement ring goes with other parts not to be washed.
Tip: label the tray sectors as in last picture to make it easier to sort and find small parts. Of course some parts will get mixed for cleaning, more on that later.
 
First, remove the balance cock to protect balance wheel and hairspring from any possible incident during subsequent work.
When removing the balance push gently the wheel from below to set it free from the fork, and avoid as much as possible suspending  the balance by the hairspring. Store it wheel up with pivot set in hole. 
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Turn movement over again to remove all dial side parts, starting with date maintaining plate screws. These can be four flat head screws, or three screws 'A' and one screw 'B' which requires the Seiko or equivalent small cross-head driver. Lift the date maintaining plate and the underneath parts will be exposed
post-1542-0-58650000-1454159392_thumb.jp
 
You can now remove:
  • Date dial
  • Date corrector wheel (white plastic)
  • Date corrector wheel E (metal)
  • Date jumper
  • Intermediate date wheel (white plastic)
  • Date driving wheel (black plastic) 
  • Hour wheel
  • Minute wheel
  • Cannon pinion
post-1542-0-44310000-1454159831_thumb.jp
 
Now, remove two date corrector wheel guard screws, wheel guard and corrector wheel C.
Note: depending on versions the date corrector wheel B can be either a separate part, or attached to the guard.
 
Turn over the movement and referring to 1st picture removing the two automatic bridge screws and bridge, and 2nd reduction wheel.
Now we can let down any tension left in the mainspring. Just keep the tip of pegwood on the barrel to prevent it from spinning to fast, with push away the click away from from the ratchet wheel. Now we can remove in order:
  • Ratchet wheel screw and wheel
  • Three train bridge screws
  • Train bridge

And will be presented with the train system

post-1542-0-38908900-1454162337_thumb.jp

 

From which we will remove

  • Click and barrel
  • Fourth and third wheels
  • Escape wheel 
  • Pallet bridge screws, bridge and pallet fork. 
Note: I recommend to not disassemble the barrel on the 6R15 movement, because a special material (SPRON 510) mainspring is used link, for which one would not find an exact replacement, and the barrel is sealed and lubricated for life. If there is any issue with the mainspring, replace the barrel complete.
 
Now, undo the single screw for central wheel bridge to remove bridge, and wheel itself. Next the keyless system, which is kept in place with two screws. There is not much tension in it but is always better to keep the setting lever in place with a stick and then lift the parts, which are:
  • Yoke spring
  • Yoke
  • Setting lever
  • Balance stop lever
My tip for last remaining parts (clutch, winding pinion and date corrector wheel A) is to just pull out the stem and pick them up from the mat to place directly in mesh basket.
 
You can now place back the balance back in the movement to protect it during cleaning, and in preparation for the next step, which is removing anti-shock upper and lower balance jewels (Diafix) . My recommended technique is the following: place the tip of the tweezers on the inside of the spring, and rotate the entire holder and movement. Once the spring is out of the frame, close tweezers and store spring in tray, pick up the jewel with Rodico, and place it directly in the metal mesh basket.
post-1542-0-41236100-1454163517_thumb.jp
 
There is one last task which is removing the 1st reduction wheel and pawl, as well the lower plate from barrel from the automatic train. Just pay attention to not lose the C-clip while pushing it out as shown in the technical guide.
post-1542-0-76695200-1454162601_thumb.jp
 
My recommendation about cleaning is that with a movement which is spotless like the one in these pictures, I do not wash all the parts, but only those that have jewels, or are to be lubricated. That means you can leave screws, some plates, plastic wheel in the tray, saving time and minimizing chances of losing them during handling. A small mesh closed basket and a larger plastic one are enough.
post-1542-0-60307000-1454161387_thumb.jp
 
For cleaning I use an household ultrasonic machine, and isopropylic alcohol only, then blow briefly with an hairdryer. Again the reason is that we only need to clean any old oil. Note: although alcohol is detrimental to shellac, I've found that even 10 minutes in there do no harm to the pallet fork jewels, but leave all parts perfectly clean without no residue whatsoever.
 
This concludes the 1st part of this walk-through.

NE15-TG.pdf

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This is my first service walk-through, for which I've chosen this well know Seiko movement. It has a lot of similarities and common parts with the 7S and 4R families. The most notable differences are

Why do you need to know this? JDM has taken a lot of time to produce a well illustrated and documented walkthrough this highly commendable of him. His way may not be your way, accept it for what it

This is the 2nd part of my 6R15 service walk-through.    Since I believe that re-assembly is not the same exactly as "the opposite of reassembly", and great attention must be given to lubrication I

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And did you just put the balance cock with the hair spring in the ultrasonic cleaner by reattaching it to the movement? I am a rookie but do have some basic skills and am very patient

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My recommendation about cleaning is that with a movement which is spotless like the one in these pictures, I do not wash all the parts, but only those that have jewels, or are to be lubricated.

A very big NO.For the sake of a few minutes if serviced properly you should have a nice watch and running, if only part of the movement is cleaned there could be something that you don't see which could harm the performance in which case you could spend more time then ever tracking down the problem. In my day if a watch came to me with a broken mainspring I would never just replace it, I would clean the movement as well, if the customer said they just wanted the spring fixed I would hand it back and tell them to take to someone else. Part repairs are nothing but trouble.

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Agree with old hippy. A while ago I fixed a loose cannon pinion on a vintage watch (for free) but in my opinion the watch also needed a service. The client did not want a service despite my advice. I expect it was because I wanted paying for the service.

Yet the client contacted me complaining that the watch was now running but for only approx 10 hrs before stopping. I did explain what the problem was & offered to service the watch but my offer was declined again !!!!!

 

Lesson learn,t never do a part fix (unless a crystal) because it will be nothing but trouble.

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A very big NO.For the sake of a few minutes if serviced properly you should have a nice watch and running, if only part of the movement is cleaned there could be something that you don't see which could harm the performance in which case you could spend more time then ever tracking down the problem.

 

Allow me to keep my opinion. Note well, I did not say "I don't examine parts", I said " I don't put in washer parts that are clean already and don't carry lubrication". I also gave a logical explanation for this choice.

In other words, explain us what is the real benefit of cleaning screws that are clean already.

 

]Agree with old hippy. A while ago I fixed a loose cannon pinion on a vintage watch (for free) but in my opinion the watch also needed a service.

Not sure what's your point. My thread is exactly about doing a full service, not doing partial fixes.

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Do you just use naphtha ?

 

Absolutely not, that just as lighter fluid leaves residue and smells terribly. Again, we are talking about parts are clean already and only need any lubrication removed, not restoring an antique lock. Note that IPA is exactly the recommended rinse solution by professional ultrasonic machines.

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I never put the balance wheel or hairspring through the cleaner. Always used Ronsonol lighter fluid never had a problem using it for about 30 years. I did try something called 1 dip I think that's what it was called came in a small jar and it was rubbish never cleaned the hairspring. Naphtha never heard of it I had to look it up to see what it is.

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Allow me to keep my opinion. Note well, I did not say "I don't examine parts", I said " I don't put in washer parts that are clean already and don't carry lubrication". I also gave a logical explanation for this choice.

In other words, explain us what is the real benefit of cleaning screws that are clean already.

The benefit is that after cleaning you can be sure all parts are clean and you can assemble the movement knowing this. You clean the movement which has the screw holes then it makes common sense to clean the screws knowing full well you now have both nice and clean. With every watch that is going to be cleaned you always dismantle everything and everything is cleaned in the cleaning machine or other. I hope you pay as much attention with the watch case as well.

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The benefit is that after cleaning you can be sure all parts are clean and you can assemble the movement knowing this. You clean the movement which has the screw holes then it makes common sense to clean the screws knowing full well you now have both nice and clean. With every watch that is going to be cleaned you always dismantle everything and everything is cleaned in the cleaning machine or other. I hope you pay as much attention with the watch case as well.

 

Be reassured that I pay attention to everything :) As stated twice before I see no point in cleaning what is clean already, and there is time saved not having to sort them out, beside avoid risk dropping or mistaking one for another. So, thank you for your opinion and experience, but I believe I'm doing what is right and works for me. 

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Tell me do you make a living out of watch repairing as to you time is everything.

Why do you need to know this?

JDM has taken a lot of time to produce a well illustrated and documented walkthrough this highly commendable of him. His way may not be your way, accept it for what it is and please don't put him off producing another.

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Why do you need to know this?

JDM has taken a lot of time to produce a well illustrated and documented walkthrough this highly commendable of him. His way may not be your way, accept it for what it is and please don't put him off producing another.

I was just asking that's all.

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This is the 2nd part of my 6R15 service walk-through. 

 

Since I believe that re-assembly is not the same exactly as "the opposite of reassembly", and great attention must be given to lubrication I will detail all the steps together with my own time-saving and risk-avoiding tips.

 

For lubrication I use the following products:

  • 9010 A.k.a Moebious A
  • 9104 to replace Seiko S-6 (note: if the watch is used outside in very cold climates, consider 9103 for pivot/stones instead)
  • 8301 to replaces Seiko S-4
post-1542-0-60974600-1454257191_thumb.jp

 

Note: it's possible to find Seiko original lubricants, but these come in big jars, so for an hobbyist it's likely the product would expire before using even the 1% of it.

The only additional tools are oilers, of which you will need one for each lubricant. These can be conveniently of different sizes. Also, I consider Rodico to be indispensable.

 

Let's start placing what Seiko calls "normal quantity" of 9104 on the sectors of the winding pinion. I understand that to be a medium sized drop of lubricant.

Tip: to easily string the wheels with the stem, place a flat piece of Rodico under the movement laid on the mat, on which position clutch and winding wheels, paying attention to the correct side. Place the corrector wheel A on the tip of the stem or on the Rodico piece, and insert the stem. With the movement back on the holder lubricate the teeth of the winding pinion and the groove of the clutch. Seiko recommends 9010 for the latter, but I do not see how 9104 would make any difference. I recommend to lubricate the stem at the time of casing only.

 

Tip: to easily install the keyless/setting do as follow, no stick pressure needed and guaranteed no flying parts.

Place a modicum of oil on the stop lever contact point in the movement trench and on pivots for stop lever, setting lever, as well a tiny bit on top the latter. Take up the setting lever, lubricate its underneath pin which it stay between arms of the stop lever. Verify that it has engaged correctly by pressing on the point marked on the setting lever and rotating it a little, the other end of the stop lever will move slightly.

Lubricate the yoke pin and top of the setting lever where the spring works. Install the yoke in its posts, but do not fit the rounded tip in the trench yet, rather leave it on the edge as shown in the picture.

post-1542-0-21030300-1454254647_thumb.jp

 

Now install the yoke spring in its posts but let the lower arm to sit above the pin of the setting lever. Fit the two screws by one turn only. Push the stop lever round tip back in place, the yoke spring to engage the pin, then tighten the screws.

 

Continue installing the central wheel and bridge. Place a small amount of 9104 on both pivots. Use the shorter screw from the train tray sector. Now reassemble the train bridge with 1st reduction wheel and pawl - use with 8301 on the eccentric, and 9104 on the tip of the long pivot. Then fit the lower plate, wheels lubricated with 9104, and screw. Note that the technical guide indicates 9010 for the stones of both escape and third wheel, however I recommend that only the respective pivots are oiled instead.

 

For the train itself we will install in sequence:

  • Barrel (lubricate arbors with 9104) and click
  • Escape wheel - this is the only one which pivots are lubricated with 9010 due to its high rotational speed.
  • Third and fourth wheel. Use 9104 for both.
Then fit the bridge, which normally it goes in place by itself very easily, just check that you have moved the tip of the click away from it, perhaps move the escape pivot a little. Of course, the train must spin freely as soon you touch the barrel is turned. Secure the bridge with the three long screws.

 

Fit ratchet wheel and screw. No lubrication here. Then 2nd reduction wheel, pinion down. Its entire circumference has to be covered with 8301; use 9104 on both pivots.

Fit the automatic bridge and its two screws, and verify both automatic and manual winding at this point.

 

The last components of this side are the pallet fork and balance assembly, but I recommend not to install the latter until the very end, to minimize risks.

 

The pallet fork installation is a bit tricky for both lubrication and fitting, Sorry no pictures here because i could not make useful ones, but here's my recommendations:

Since the consensus is to not lubricate pallet fork pivots i I don't do that, even if the guide indicate otherwise. Using a good loupe slightly lubricate the face the pallet jewels, then with a tip of Rodico I clean them around. Oiling the escapement teeth simply doesn't work for me.

To fit the pallet fork, as it's quite easy to snap the upper pivot. I use the following technique.

Give a a couple turns to the barrel. This helps keeping the fork steady once in contact. Fit the fork and positively bring the bottom pivot in the hole. Since the escapement teeth are in the way, the fork cannot find its position yet, so just put the bridge in its posts, you may also present the screws with one turn only. With the stick place a very light pressure about the holed jewel. Now observe the impulse arm of the fork, bring it to be it horizontal with the tweezers tips. At this point you may hear a faint click, the fork moves to one side and the bridge now stays horizontal under the stick. Maintaining very light pressure check, double check and check again that the fork can move side to side without changing inclination and escapement turns. Only then tighten the screws.

 

We can now move to the dial side, the very first component to be installed is the balance anti-shock. I do lubricate the cap jewel (flat side) with a drop of oil about one third of its diameter. It is actually quite difficult to dose and center the right amount. Also, sometime telling which is the flat side is problematic, as one risk to make it fly as it probes on the edges. I then place the jewel frame upside down on the cap jewel, grab it with tweezers turned down, and bring it to its place. To fit the spring I use No. 5 tweezers, sliding one side a tiny bit first, then the other. I have no problem anymore doing that but it's always better to keep the tip of a dry oiler in there for safety.

 

Once that is done continue lubricating the arbor for date corrector wheel C with 9104. Then fit the wheel, which can be placed either side indifferently. For the other wheels which are fixed to the main plate or to the guard put a small drop of 9010 (for its better penetration) in the machined sector on top, as the guide shows. Reinstall the date corrector guard with the two screws, note the guide indicates a different part number for these, but I've measured all to be exactly the same.

 

Install the cannon pinion pushing it down to click in place. Lubricate slightly its two contact rings with 9104, as well as the arbor for the minute wheel on the main plate. Install minute and hours wheels. Follow with the black date driving wheel, and the white one, with the dot up. Check the working of the time setting.

 

Lubricate the arbor of corrector wheel E (can be bronze color ) and install it, then the white plastic date corrector wheel, and date jumper plate. Check that advancing the time the upper arm of the date driving wheel goes above the plate as in picture below.

post-1542-0-94806100-1454256068_thumb.jp

 

Now place the date dial well centered and the maintaining plate above it on its posts. Do not worry about the date jumper engaging yet, it will happen by itself as you fit and tighten the screws. Give one last check to all setting functions.

 

Time to reinstall the balance, which is possibly the most difficult task.

First, make sure the stem is full in, otherwise the stop lever will prevent installation very effectively.

What I do is to observe which side the pallet fork stays before bringing balance cock and balance to the movement. Move the wheel very gently to find the lower hole, with the balance cock in the correct position, but out of it's post.  Then lifting and turning the balance slightly in the direction the fork was resting the balance will start swinging. Only then fit balance cock and tighten screw.

The last task is refitting the upper anti-shock jewel, and hopefully all will be good for regulation on the timegrapher.

 

After casing the movement you can fit the rotor weight, For maximum efficiency of automatic winding remember to align the hole on the reduction wheel with the post on the bridge and screw in the weight at 3, as the guide explains.

 

This concludes the 6R15 service walk-through. 

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Hi JDM,

 

Nice walkthrough, I did one, some time ago, for the newer version of this one, the NH36, -- or maybe the same with a different marketing name? -- here:

 

http://www.watchrepairtalk.com/topic/1635-seiko-nh36-walkthrough/?hl=nh36

 

I believe that with Lawson's 7S26 walkthrough, all these walkthroughs complement one another nicely...same family, and show their evolution.

 

Your oil equivalents are very interesting. There is more about them here if you search for lubricants. Nevertheless, for Seikos, I use the Seiko lubricants readily available on the bay with exception of the Moebious 9010 that, as you so rightly point out, is the "A" type they talk about in their spec sheets.

 

Nicely done although I disagree with the "cleaning only the oil" part. Best practice indicates everything should be cleaned...but I suppose it is a personal preference. In a hobby thing I believe everything is valid!  :)

 

Keep them coming!

 

Cheers,

 

Bob

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Nice walkthrough, I did one, some time ago, for the newer version of this one, the NH36, -- or maybe the same with a different marketing name? -- here:

 

Thanks. It's not the same. SII NH36 = Seiko 4R36, the differences to the SII NE15 = Seiko 6R15 are mentioned at the beginning of my post.

 

I'll try one last time to explain why I do not wash clean screws, or even clean plastic wheels: I do not want to risk dropping or confusing them and do not enjoy handling things without a specific purpose.

So far nobody had given a better objection other than "best practices" or routine, but that is an empty statement compared to mine. 

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