Service: Longines Conquest Heritage calibre L633.5 / ETA2824-2

Tom sent in this great looking Longines Conquest. Super classical look, and I like the date at the top. Unfortunately, it is a bit ill and needs some TLC. It sometimes stops randomly, and doesn’t keep good time.

Well, that doesn’t look good and explains the trouble Tom is having with the watch. This is what I call “someone spitting on the timegrapher screen”. No wonder the watch is having problems.

Longines brands this movement as a calibre L633.5, but it’s an ETA 2824-2.

This is a high-quality movement, and a quite accurate one as well.

With the movement taken apart, we’re ready for the cleaning machine.

I’ve ordered an new mainspring and crystal, and can now start to put the movement back together.

The movement is coming back together, with the gear train already in place.

That is what I expect from an ETA2824-2. I will do a final adjustment before closing the case.

The bottom plate back together and ready for the dial.

The dial is in great shape.

I test if the watch is watertight, and the leak tester says yes.

What a beauty.


25 thoughts on “Service: Longines Conquest Heritage calibre L633.5 / ETA2824-2

  1. Pingback: Kara Kho

  2. Hi , I purchased the Longines “Conquest” two weeks ago and I am happy with it over all and consider it a beautiful watch for the price and for what I want for a nice simple dress watch .However I am a little disapointed to read that the emblem is stuck on with glue, is this a common practice these days ? I was wondering if the Longines “Conquest” watches from the 1950s & 60s had thier emblems stuck on with glue as well?

    • I bought one of these a six years ago. Within the first couple of weeks I put it down on a stone worktop and the gold logo on the back of the watch just fell off. I was very disappointed to find that it is a hollow pressed piece of thin gold sheet and yes, it was held there with glue. Felt conned.

  3. I have this exact same model. Lovely watch, with one of the most tasteful dials on the market. If only Longines had adorned it with an alligator strap instead of the – admittedly high-quality, but plaintive – nappa one, it’d be even more beautiful.

    • Looks like a custom grade. It has a level of decoration. And the “better” incabloc shock system. But doesn’t have the nicer Glucydur balence as you can tell by the spokes, so it may or may not have the nicer mainspring or hairspring materials.
      Looks like an in between of a elabore and top grade. Which would make sense for this watches price range.

  4. Are the Longines Legend Diver watches (with L633 movement) parts from China? Mainly, is the Case and Caseback made in China? I would really like to know….Thanks! Jack

  5. I have had got a Longines conquest watch can you tell me is there any issues with this watch i have had it for 4years has been back to shop 3 times once when the glued back came of,time was loosing,now it has stopped working altogether.Thanks Mr S Cooper

    • I can confirm that there is an issue with your watch 😉
      Once my psychic capabilities are fully developed, I will remotely diagnose the problem. In the meantime, grab a repair slot from the booking page and send the watch in.

  6. Thank you for detailed information. I have exactly same model of Longines. I have two questions.
    1. If I try to wind this watch manually, after few turns, it becomes hard to wind it further.
    Is it normal with this movement? Generally automatic watches do have a mechanism which prohibits from over-winding the watch.
    2. I have bought a watch winder, for this watch should I keep it on ‘anti-clockwise’ or ‘bi-directional’ setting? Please advise. Thanking you in advance.

    • Automatic watches are most of the time harder to wind than manual watches as you have to move parts of the auto wind mechanism as well. You can’t overwind them, but there is no distinct stop as in a manual wind.

      Bidirectional setting is fine.

      Best regards,


  7. I have a question about this watch.

    I bought one of these recently (brand new from a reputable Longines Authorised Dealer in the UK) and after just a few weeks, the enamelled medallion on the back (photo: came off.

    I had assumed the medallion was an integral part of the same piece of metal as the rest of the case back; not only was that not the case but it was glued on in what seems to have been a cheap and flimsy way.

    My question is this: when you worked on this watch, did you notice anything else particularly cheap about the way it is constructed? For example, how is the back made – is it milled/machined and solid, or is it a stamped-out part? How are the indices applied to the dial – are they fixed well, or might they be the next thing to come unglued?

    I like the way the watch looks but now I feel I’m wearing something rather cheaply made. What was your own impression?

    • For the price you paid, you good a good watch, with a good Swiss movement. Don’t be too disappointed that the enamelled bit came off the back – it would be pretty hard to make that from one piece 😉

  8. I have a watch the same as this (purchased 1959 )without the calendar but the face of the watch isnt nearly as clean as the one above and has marks on it . Can anything be done for that or are replacements available ?It still keeps excellent time .thanks John

    • Longines might be able to help you, or you could have the dial restored. It will look slightly different from the original, but it’s a workable solution.

  9. I like the date position – the whole design in fact. Was it already set to 12 or did you do that just for the photo..?


Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.