The festive break has allowed me to get the blog updated a little and catch up with a few jobs, one of these jobs being my 6159-7001. I’ve owned this watch for a few years now and as I’ve sourced the parts I’ve installed a NOS bezel, crown, crystal and seals in that time . Although it’s always run acceptably at about +15spd I’ve always been meaning to service it just so I know it’s the best it can be. Well I found the time over the break and it’s finally done! As can be seen cosmetically it’s in outstanding condition with an unpolished case which is just how I like my watches.

The back of the case shows it has a production date of March 1969. No caseback on these of course as they are of a monoblock construction, the case was derived from the earlier 300m 6215-7000 but has a better crown system (the 6215 has a split crown which can be a little temperamental) and a much better sealing system for the crystal. These advances allowed Seiko to label it as their first “Professional” dive model, a range which is still in production today.

With the bezel removed you can see the crystal retaining system, instead of a threaded retaining ring like the 6215 had, this has a ‘wedge’ type locking ring which is fitted into the three slots and turned clock wise by about 60 degrees or so to compress the main crystal seal.

With the locking ring and crystal removed the main seal is now visible.

Here’s a shot of the bezel and crystal components now they’re removed. There is also a nylon washer that is still fitted to the crystal which prevents any damage when the locking ring is tightened down.

With the main seal and chapter ring removed you can see the stem release button. I’ve removed the hands before removing the movement to reduce the chance of any accidental damage!

A shot of the empty case.

With the dial removed the movement is turned over and placed in the holder to start the strip down. The rotor is removed in this shot so you can see some of the witness marks on the mainplate. These are caused when the rotor bearing is worn, however the bearing in mine appears to be fine so I presume it has been replaced at service time at some point in the past.

With the autowind bridge out of the way the typical 61xx architecture can be seen. The biggest difference between the 6159 and most other 61xx calibres in this view is the upper crown wheel which allows for the hand winding of the movement. Of course all the train wheels are different being that this is a high beat (36,000bph) movement.

The balance assembly and fork are the next components to be removed, note the upper barrel jewel, a lovely touch.

Just a note about the pallets, my watch was running very well with a nice steady trace on the timing machine, the only sign of not being at full health was a reduced amplitude. With the pallet fork removed it’s obvious it was in need of a service, I’m amazed the figures looked so good when you look at the filth on end stones. It just goes to show that just because a watch keeps reasonable time doesn’t mean it’s not in need of a service.

With the train bridge and wheels removed the barrel comes into view with its famous “Do not open’ script printed on the lid!

The barrels lid is crimped in place to prevent it being opened, these were always replaced as a unit when serviced but of course 50 years on the absence of any replacements made me determined to get these buggers open! I’ve developed a system for safely doing it and more importantly get the lid properly back on, if there’s any doubt about servicing these barrels just look at the muck inside of this one 🙂

The movement is turned over and the dial side can be stripped.

Underneath the top plate you can see the calendar mechanism which is pretty standard 61xx calibre apart from the extra stem release lever. Another point of interest is the pallet fork jewels have a crimped in dust cap to keep the pivots free of any debris.

Just the keyless work to remove now.

And the watch is fully stripped ready for cleaning and inspection.

The rebuild started with the mainspring as is usual with me! You can see the thicker gauge of the spring compared to lower beat movements, this allows a more consistent delivery of power due to the higher gearing of the 36,000bph train.

The wheel train’s the next part to be fitted, note the brass hacking lever under the third and fourth wheels.

The train bridge is next….

….followed by the pallet and balance. The power was wound on then the movement had its rough timing adjustments done.

Although the autowind bridge appeared fine I had a NOS bridge in the parts drawer so I took the opportunity to fit it.

The only signs of wear on the old one were some rubbing marks on the underside from the pawl legs.

Another interesting point (to me anyway!) is that the pawl has a blind jewel, it’s covered by a pressed in metal plate. It helps to keep the lubrication where it needs to be I suppose 🙂

The autowind mechanism was replaced and this side of the movement was completed.

The movement was turned over and the dial side rebuild commenced.

With the dial side completed I turned my attention to the hands. These still retain their original lume but the minute hand has a crack down part of the middle. I’ve always been wary of this being a potential problem if the case were to take a knock so I decided to stabilise the lume.

Lume binder was used to coat the backs of all the hands, this will strengthen the compound and should help prevent any premature loss. Sounds like a baldness remedy 🙂

The dial and handset were then refitted….

….the rotor was refitted….

…and the movement replaced in the case.

The chapter ring and main seal were re-fitted….

….the crystal, side seal and locking ring were replaced….

….and the bezel was popped back on. All finished now and running beautifully, it’s just a shame it’s taken me a couple of years to get around to it. I’ve been thinking it’s getting near the time for a change and so I could possibly be persuaded to part with this beauty, if you’re interested in buying one of the best 6159 divers out there let me know before I come to my senses!

*Edit* The watch is now sold so need for any more messages about wanting to buy 🙂