Seiko 7002-700J Diver

Fixing my brother’s daily wearer

If you are a long time reader of this blog then you may recall a post made in December of 2017 regarding a similar watch which I restored for my father. I actually had set out to do two watches- one for my dad and the other for my elder brother with the intention of having both ready by Christmas Eve. Well, all went well with my father’s watch but my brother’s turned into a fiasco.

I purchased my father’s watch, a Seiko 7002-7000 Diver from a well respected eBay seller who goes by the handle thewatchcollector. To my knowledge he’s based in the Philippines and he moves a lot of Seiko watches which are generally sold in lots. What you see is what you get and although the pieces will be well worn there are not a whole lot of unexpected surprises inside.

For my brother I took the extra step of sleuthing out a Seiko 7002-700J as this was the Japanese Domestic Market (“JDM”) version of the 7002 Diver which made it a little more special than the rest. Firstly, the 7002A movement inside was manufactured in Japan as opposed to Singapore and this was clearly stated on the movement. Next, the dial proudly displayed the text “Made in Japan” and also the number of jeweled bearings inside (17). Last, the rotating bezel was a combination of red and blue instead of black.

Now all this was important to me because my brother has always had a strong connection to Japan and has spent time both living and working there. So it seemed that if I was going to give him a watch it should not just be a Seiko but a properly made in Japan Seiko.

Well, this turned out to be easier said than done. Anyone who has looked into purchasing a 7002 Seiko Diver knows that it’s the most modded watch in the world. If you are looking for a proper original piece then you’d best go to the seller I noted above. Unfortunately at the time I needed one he didn’t have a 7002-700J that still had the original movement, dial, and bezel. So I needed to look elsewhere and the clock was ticking if I was going to get this done by Christmas!

When I finally found the piece I was looking for it was in India and that alone should give you pause. I know now that they are better ways to grab JDM watches but at the time I was under the gun and eBay was my go-to solution. India is not the best place to find vintage watches for restoration. In the watch community watches from India are known for having a rough life and often being cobbled together from parts of other non-runners; and let’s not even bother to remember the fact that I’m looking for a watch that was only sold in Japan and when I find it it’s in India…? Not a good sign. Tropical locales, be they India or the Philippines, are well known to torture a watch.

Throwing caution to the wind I made the purchase and when the watch arrived this is how it looked:

I’ll admit this looked worse than I had expected when it arrived

So this wasn’t great. The dial, although it’s correct, was about ten degrees out of place suggesting broken dial feet. The luminous paint was completely ruined. The bezel insert and crown were missing; both are replaceable but a missing crown in a in a humid environment is never good.

A peek inside confirmed my fears about the humidity.

Rust is like cancer

Oh my, it wasn’t water ingress that had ruined the dial- it was oil!

Lots of oil on the dial

My heart sank and I pulled the movement from the case. The dial was in a bad way and I was unsure if it was salvageable. I thought perhaps if I could clean up the oil and reapply the luminous paint there may be hope.

I still had hopes to salvage the dial but they were fading fast

It turned out the whole watch was bathed in oil. It’s usually laughable when this happens. Someone must have said, “Just add more oil and everything will be fine!” and of course that’s never true. I must admit to being more irritated than usual.

More oil where it should not be

Removal of the dial revealed something unexpected- a Day Wheel. This movement had a day-date calendar even though the dial only had an aperture for the date. Strange.

There was a Day Wheel hiding under the dial

Beneath the Day Wheel were all the parts necessary to make it work, so this really is a day-date movement!

In fact there are all the bits for this to be a Day-Date watch

Now is the time, dear reader, when any intelligent person would flip the movement over and read the model number but apparently I’m not one of those intelligent people! It was a few steps further in the process before it finally struck me that I had the wrong movement in my 7002 diver watch.

Disassembly of the calendar mechanism revealed cap jewels on the Third Wheel and Escape Wheel. “Boy, these made in Japan 7002 movements sure are exquisite” I surely whispered to myself.

Here we have the calendar works and… cap jewels?
Getting down to the Main Plate

I finally realized this was the wrong movement for the watch when I flipped it over and began work on the autowinding mechanism. With the Oscillating Weight removed you can clearly see this is a Seiko 7019A movement. A better movement than the 7002A and one made in Japan to boot, but not correct for the watch.

With the Oscillating Weight off it’s easy to see this is not a 7002A movement

The cussing must have begun at this point because the pictures stopped being taken. Below is the final picture of the service of this movement.

A look at the 7019A Going Train

I don’t recall all of the shenanigans that subsequently ensued but from the pictures it’s clear I had a new bezel insert, crystal, and crown by the 21st of December and had managed to procure a proper 7002A movement by 23rd of December.

New crystal with gasket and bezel insert
Here’s the 7002A movement (with some extra bits installed for a day of the week complication
The proper “Japan” Oscillating Weight on this movement

I know the watch wasn’t ready by Christmas Eve because my brother received this (below) along with an “I Owe You” instead:

Come Christmas Eve, this was all that was ready

With the Christmas deadline behind me I got back to work and cleaned the dial of the old luminous compound and oil. Although it looked better, the cleaning revealed even more damage and so I grudgingly let go of it.

The oil has been removed along with the luminous paint- there are lots of scratches though

I assembled the watch with the newly procured 7002A movement. I ended up using the same aftermarket dial as was used on my father’s watch and delivered the assembled 7002-700J to my brother for what I hoped would be a good life. I have to admit I was not happy with this outcome though. I wanted him to have a proper, original, Seiko 7002-700J and what he ended up with was close but not perfect.

Aftermarket Dial and Hand Set installed on the 7002A movement

Regrettably, I forgot to take a picture of the watch as it left my workshop so you’ll never see what what the final restored version (we’ll call it version 1.0) looked like in early 2018 but as luck would have it this watch has led a very eventful life since my brother took ownership and because of this I would get to see it twice more.

In early 2019 the watch was lost only to turn up again several days later- apparently whoever picked it up felt it was too hot to hold onto. My brother had told me at the time it was running slow but it didn’t come back to me until November of that year when the autowinder failed. It looked good when it returned.

Still looks good after about two years of wear

I was actually pleased when it came back because both my father and brother had commented that the power reserve was lower than expected. I learned that I had used the wrong grease in the Mainspring Barrel– it was too slippery for an autowinding movement, and I was keen to fix this. Having my brother’s watch back after several hundred hours of use would also give me an opportunity to grade my earlier service.

The watch was a little dirty on the outside but looked almost as I had left it on the inside.

Movement in the case prior to cleaning
Oscillating Weight removed

A little concerning was how dry the Balance Wheel pivots looked under the cap stone. The Balance Wheel pivot should sit in the center of a small pool of oil. It will dry over time but I was surprised to see very little oil remaining just two years later. Poor marks here for sure.

The jewel for the Balance Staff looks dry of oil

The fault that caused the watch to be returned was the failure of the Second Reduction Wheel – the wheel had rusted where it meets the post upon which it rotates. The constant motion of the Second Reduction Wheel resulted in the rust grinding away at the bearing. This caused the Pawl Lever to be damaged as well.

The damaged Second Reduction Wheel post

The Second Reduction Wheel rotates perpetually since it’s part of the autowinding mechanism. As a result, the rust from the wheel was scattered throughout the movement and picked up by the oil in the bearings. Everything would need to be cleaned and re-lubricated.

Rust has fouled the oil for the Third Wheel

To repair the damage I burnished the post and replaced the Second Reduction Wheel and Pawl Lever then fully cleaned and lubricated the movement before reassembling, testing, and returning the watch to my brother.

It’s been a few years since then and the watch has had another interesting journey. My brother moved to Japan so the watch essentially returned home. It got a lot of wear but unfortunately suffered a fall which caused the Sweep Second Hand to pop off. A watchmaker in Japan offered to service it but the cost was high so it was held onto it until he returned stateside. I offer lifetime free service to family members and was happy to take on the work and see my old mechanical friend.

Back again after a fall

Always failing to have the proper tool for the job, I still don’t have a good set of caseback dies so I resorted to the old duct tape method of opening the case; it took a bit of elbow grease but I prevailed in the end.

The caseback probably should be tighter if this method works

Putting a bit of wind into the watch gave me a pretty good reading on the timegrapher. In fact I don’t recall this movement every displaying such good amplitude. Little did I know this was foreshadowing what was to come.

A good initial reading – running too slow though

I took the whole movement down. The post for the Second Reduction Wheel displayed unwanted grit (again) and this was concerning but otherwise things looked pretty good.

Movement ready to come out of the Case again
Not too dirty under the dial
The calendar works look good – at some point I put in a Date Ring with crisp numbers
Only the Balance Wheel and Fourth Wheel are a gold color
The Second Reduction Wheel post looks bad again – this will be addressed with a new bridge
Mismatched wheels but it still works

You can see a lot of the story of this watch in the images above- the grime on the Second Reduction Wheel post, the mismatched brass Fourth Wheel, the wear on the top of the Barrel Bridge where the Ratchet Wheel is rubbing, and of course the scratches everywhere!

There was a problem though. The jewel for the First Reduction Wheel in the autowinding mechanism had a big chip taken out of it. This jewel would need to be pushed out of the bridge and replaced, and this is where it went off the rails.

Damaged jewel bearing for the First Reduction Wheel

First I damaged the Barrel Bridge removing the jewel and by “damaged” I mean ruined. I used a stake which was slightly larger than the jewel hole to push out the jewel and this resulted in deformation of the brass all the way around the jewel hole. This maybe fixable but the lack of skill I showed in making the mess took away the confidence needed to clean it up.

So to fix this error I replaced the bridge entirely but that resulted in an unexpected loss of amplitude. Hmmm… I determined that I needed to jewel the bearings for the Mainspring Arbor– top and bottom. Well by the time I had borked that job, I needed a new Mainplate for the movement. Then I discovered the extended pivot of the Fourth Wheel was partially missing- did I break that too? Pretty soon I had enough parts to put together a second 7002A movement.

In pieces – two Mainspring Barrels as I tried out multiple Mainsprings and chose the best

Well hey, it’s only the best for my brother’s watch so now gone are the mismatched brass wheels and hello to the new jewel for the Mainspring Arbor.

A new jewel for the Mainspring Barrel Arbor
What a Balance Jewel should look like when oiled

Hours were spent cleaning parts, burnishing pivots and swapping out this for that to get the movement back up and running well. I think I’ve now had a total of three 7002A movements volunteer as donors but in the end I finally had something darn reliable.

Finally able to table the movement, I thought I would try and tackle the balky Bezel Click which had never sat right with me.

Seiko had changed the design of the bezel click halfway through the 7002 production run. In the early design, a ball bearing, housed in a sleeve and under tension from a coil spring, would fall into the grooves machined into the underside of the bezel. This allowed the ring to move in both directions with a fairly smooth clicking action.

The drawback to this design was that the ball bearing was prone to seizing up when dirt and grime would accumulate under the bezel. Even if the ball bearing didn’t seize up, the dirt would act as an abrasive and slowly eat away at the edge of the sleeve which had been rolled over to hold the ball bearing in place. Eventually the ball bearing would pop out and skitter away (that’s how the watch came to me from India) leaving the sleeve and spring behind.

The ball bearing for the bezel click vanished as soon as the bezel was removed
The coil spring wants to leave the sleeve

The quick and dirty fix for this is to acquire an aftermarket ball bearing and push it back into the the sleeve; it will want to shoot away but if you get the bezel in place quick enough you can lock the ball in place. The bezel will squeeze the ball bearing about halfway back into the sleeve, but the movement action is not terribly smooth and without lip on the sleeve to hold it in, the ball bearing floats between the Case and the bezel creating a larger gap between the two. This gap will fill with grime and eventually seize up the works again. Way back in 2017 this was the solution to the broken bezel click; this time I hoped to devise something better.

A lightly worn bezel is the best looking bezel

I pulled the sleeve from the case and cleaned it and the coil spring in the ultrasonic cleaner. I then used the lathe to hold the sleeve and loaded it with the coil spring and ball bearing- the latter being pushed into the sleeve using a 0.65mm steel rod held in the tailstock of the lathe.

The setup used to reseat the ball bearing in the Bezel Click assembly

Then, while the rod from the tailstock compressed the ball bearing and spring within the sleeve I used an unsharpened graver to fold over the steel edge of the sleeve. This secured the ball within the sleeve but allowed it to rotate when the Bezel was turned. A proper fix.

Case cleaned and Bezel Click repaired

Next, I turned my attention to the dial. As I stated I was not happy with the aftermarket dial even though it was of pretty good quality. I needed an original for this piece to be correct. Lucky for me, I had an opportunity to rectify the this issue as a proper replacement popped up on eBay. This one was in exceptional condition considering its age- most original 7002 dials suffer from Lume Rot where the Promethium based luminous paint absorbs moisture and appears to grow black mold. It’s a hideous look and there are scores of such watches floating around eBay so finding a good original dial can be really difficult.

Clean movement ready for testing
Dial side – Is this Mainplate from a Seiko 7009 movement?
The correct original dial for this watch is installed

The dial even came with the original handset but sadly the plating on the hands had been damaged at some point so I reused the aftermarket handset I had acquired back in 2017; the original dial and aftermarket handset go together quite well as the luminous paint on the hands is a close match to the luminous paint on this dial.

I was getting near to finishing this job up but wanted to make sure the seals were all good so I replaced them with a new set made of Fluorosilicone. The previous set of gaskets and o-rings was only five years old but the o-ring for the crown had frayed and I felt it was better to be safe than sorry. The Fluorosilicone will hold up as good as rubber but has the added benefit of being tougher in the presence of hydrocarbons such as gasoline and kerosene. I’ve used these seals on my MK III compass projects earlier and found them to be tough as nails. If you’re doing your own 7002 project you can grab a set from Vintage Time Australia.

New blue gaskets

The last thing to do was to case up the watch movement and start testing. Since most of the watches I do are my own and get little wrist time I can slack off on the vigorous testing but this watch was different and I needed to make sure it was well regulated and that the autowind was working without fail.

Re-cased with a new crystal

The first order of business was to wind the movement using the test station which will rotate the watch through all six positions (dial up, dial down, pendant up, pendant down, pendant right, pendant left) repeatedly. This continuous rotation will provide the kinetic energy necessary to rewind the Mainspring and it has the added benefit of providing feedback on how well the watch is keeping time through the movement of multiple positions.

The reading is a little fuzzier when it’s listening for ticks through the thick case

The results of the tests have been positive thus far. I’ve been testing the watch for over a week now and it’s keeping impeccable time. The readings from the timegrapher mirror these results as registered gain/loss is under +/- 15 seconds in each position. Furthermore, the amplitude has continued to rise a bit each day tested. My only complaint is that the power reserve is not where I would like it to be and the mainspring will run out in less than 36 hours if the watch is left untouched.

The bracelet is reattached with tightened end links

Earlier, back when I had the movement on the bench, I had tried three different Mainsprings– looking for the one which provided the most amplitude and longest power reserve. All of these springs were pulled from donor movements though and it might be that a brand new spring is needed to get the power I’m searching for. I’ll advise my brother of this when the watch is returned and let him decide if we should go the route of ordering a new spring. If the watch is worn regularly enough the spring will probably remain near full wind negating the need for replacement but we’ll see how it plays out.

The very last steps were to order a brand new crystal from Klein Vintage Watch and apply new binder to the luminous markers on the dial. The binder (lacquer) should keep the Promethium paint from flaking off for several more years and the brand new crystal is the chef’s kiss.

My brother has been immensely proud of this watch but I was disappointed that what I had provided for him never quite reached the standard I originally set for myself. This is a common scenario for me. Hopefully he digs the new dial and watch runs better, and for longer, than it has before. Whether it does or does not, if he keeps bringing it back I’ll always ensure it’s returned returned to him in top notch condition. I’m sure there are even more improvements, more performance to eek out of it. I just need to keep sharpening those skills.

Seiko 7002-700J – service completed

Oh one last thing- in doing my research for this post I happened to come across the original Owner’s Manual for this watch. I’ve linked it below for all who are interested or may need it. Cheers!

Seiko 7002 Owner’s Manual

Author: JPMoeller

Amateur watchmaker and California resident

One thought on “Seiko 7002-700J Diver”

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

%d bloggers like this: