Another apprentice project I have bought is this Longines sports chief.
The dial shows some water damage, dirt and the second hand is missing. I did not see the state of the movement when buying this watch online and if there has been water in the case it can spell disaster.
I’m lucky as the movement looks to be in excellent shape.
Performance is better then expected but definitely in need of a service.
I start by removing the cap jewels. I need to take extra care not to loose these cap jewels, as they are transparent, colourless and almost invisible.
I remove the balance.
Before removing the wheel bridge I remove the ratchet wheel and crown wheel
Here you can see the gear wheels
The sweep second wheel won’t come out.
And this is why. The pivot where the second hand attaches on is bent. I try to straighten it but it snapped off. However all is not lost as there is plenty of pivot left to attach new second hand.
The mainspring is in a sealed unit so I won’t run it through cleaning fluid. I clean the barrel with rodiko and oil the barrel arbor.
The last of the disassembly is usually the setting leaver and spring.
Organised chaos;)
I start by oiling and fitting the cap jewels so that I can check that the balance is moving freely. On this movement I need to assemble centre wheel pinion and minute wheel so that I can screw down the bridge that holds everything in place. I’m doing this since the bridge also has the lower pivot jewel for the third wheel.Here you can see the barrel, centre wheel and third wheel back in place under the barrel bridge.
Centre second hand and escape wheel and wheel bridge back in place.
Escape wheel and forth wheel under the wheel bridge. 
I now have a beating movement. 
Timegrapher results are without doubt excellent.
I now assemble the winding mechanism
Everything back together working and waiting for dial and hands.
I only lightly brush the dirt away as the lettering is very sensitive to cleaning.
Movement back in its the case and looking great.
With a new second hand this watch once again looks really classy.
Update.
The watch was not being worn much as the dial did not look that great. I sent the dial to our guy in Spain and the long waiting time is worth it. They could not do the sunburst pattern due to fixed markers, but we agreed to only wash away the old varnish and lettering print and keep the original finish. I think the result is stunning as I have the original dial finish with fresh printing and varnish that is very close to how it was new!
And now the watch is being worn much more!
Hi there,
Who is the dial person in Spain?
Thanks, Steve.
They are called Danafi – you should be able to find them on Google.
I have a Longines with this movement and it’s a great performer. I’m curious though; with a sealed barrel and not cleaning it, how do you ensure the mainspring doesn’t need to be replaced and that the oils inside aren’t dried out or in need of replacing?
Yes theoretically that is the best option, but as the unit is sealed I decided to leave it. Next time I will probably try to open it and clean/replace the mainspring. I also have a NOS barrel with mainspring in the workshop;)
I also have this same movement in a different case, and the mainspring is in need of replacing. Can you share where you sourced the NOS barrel? Is it possible to replace only the mainspring? How difficult would you rate replacing the barrel on a scale of 1 (easy) to 10 (hard)?
Hi Doug,
Keep an eye on ebay. They show up from time to time, you could also try open the barrel and measure the old mainspring and see if there is anything available that matches. I would rate replacing the barrel at 2. Replacing the mainspring in a sealed barrel at 8.
And if it fails, we will buy the parts!
Thanks both of you for replying. I’ll keep a lookout on ebay. Actually mine is still running fine, having just been serviced, but the recently replaced MS slips in the barrel after about 10 winds, resulting in the need to re-wind about every 12 hours. It makes me wonder if the new MS is the proper one. It is supposed to have a T-end that catches in the barrel cap. I thought with NOS parts slowly disappearing, I should try to source a sealed barrel sooner than later. The mainspring is still available at cousins for £11.95. I purchased one of them already.
Do you have an approximate value on an original longines manual winding wristwatch running very well and in excellent condition? I would appreciate some advise on this.
Hi Steve,
I’m afraid we don’t do valuations. Please check completed auctions on eBay.
Hi – I have a Longines 280 movement for which I am trying to find a case – new or second-hand. Is it possible for you to tell me what the case number is for the 280 you’ve described in this blog. Some suppliers require a case number to search their databases.
Any info you have would be much appreciated.
Will
Sorry, but I don’t have the case number on my records.
Best regards,
Christian
Classic!! 🙂
That is very nice.. though I think the second hand may be a touch long 😉
You might want to buy an ultraviolet light source… many jewels glow in an interesting manner when exposed to UV – might make it easier to keep track of them!
Hi Cirrus
That sounds interesting with the UV light! Also makes scorpion hunting fun;)