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Finished Valjoux 7750...scared to change crystal!

noirrac1j
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noirrac1j Distinguished Member

noirrac1j

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Hello,

I just finished this Lorenz chronograph with a 17 jewel ETA 7750 powering it. I had some rough patches when I lost the chronograph wheel friction setting and the hour lock. I ordered new ones and things went OK until I misplaced the hour counter wheel and had to go back in. After that I adjusted all the settings, which took removing the chrono wheel, hour counter, and minute counter hands twice to get them perfectly centered and resetting properly. Now I look at the crystal and my confidence wavers because I've never changed a glass crystal and this one is curved. I have all the tools needed, but would like not to break the crystal removing it in case a replacement turns out to be a challenge. Any input is appreciated. I'm not going to post all the pictures of the overhaul because @Lawson has done that to perfection already. Thanks to @Mark for his excellent video repairing the rusty Breitling whose owner was pushed into a pool.  

JC

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RyMoeller Super WRT Addict

RyMoeller

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Wow, you've already climbed Everest!  Don't be worried about coming down the other side.  Surely replacing the crystal is the easiest part of servicing that beast!  :Bravo:

I applaud your efforts.  I'm still looking forward to my first 7750 service!

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noirrac1j Distinguished Member

noirrac1j

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47 minutes ago, RyMoeller said:

Wow, you've already climbed Everest!  Don't be worried about coming down the other side.  Surely replacing the crystal is the easiest part of servicing that beast!  :Bravo:

I applaud your efforts.  I'm still looking forward to my first 7750 service!

Thanks Ry. I'm going to wear it for a few days and then go ahead and try to remove the crystal for sizing. If I can remove it without breaking it, I'll feel better....

It's a very good timekeeper, so now I know what all the fuss was about--very well made.

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Cad101 Super WRT Addict

Cad101

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Marks video on how to remove a watch crystal is probably the best I've seen. I was the same as you a bit scared but I followed his vid and had no problems. Is it crystal or plastic with a slight dome.

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bobm12 Distinguished Member

bobm12

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Good job Joe, that's a beauty of the watch and what a movement! Love those! Now, don't tell me you got cold feet on the crystal!! You know you can...go ahead, but hurry, I'm holding my breath! :)

Cheers,

Bob

PS. It deserves a nice crystal, maybe sapphire? Is it possible? The shape doesn't offer much protection so the better crystal will keep a long time without scratches.

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noirrac1j Distinguished Member

noirrac1j

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5 hours ago, Cad101 said:

Marks video on how to remove a watch crystal is probably the best I've seen. I was the same as you a bit scared but I followed his vid and had no problems. Is it crystal or plastic with a slight dome.

It's crystal (glass) with a slight dome. I forgot that I belong to the finest watchmaker/hobbyist site on the planet....gotta check out those vids!

JC

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noirrac1j Distinguished Member

noirrac1j

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13 minutes ago, bobm12 said:

Good job Joe, that's a beauty of the watch and what a movement! Love those! Now, don't tell me you got cold feet on the crystal!! You know you can...go ahead, but hurry, I'm holding my breath! :)

Cheers,

Bob

PS. It deserves a nice crystal, maybe sapphire? Is it possible? The shape doesn't offer much protection so the better crystal will keep a long time without scratches.

I'm gonna give it a shot later. The watch deserves to have a nice crystal. You're right about the shape not offering protection with that domed-topI. It's a nice looking mechanism and is working fine. I'll probably go to Borel and see what they have.

 

JC

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  • 2 weeks later...
noirrac1j Distinguished Member

noirrac1j

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Good evening,

I finally got around to replacing the crystal on my Lorenz 7750 chronograph. Replacing the crystal wasn't that hard, but I did have to order the crystals twice because the first was too small.

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I also noticed a problem that another forum member was having: the hour counter indicator was constantly running. I reopnened the watch and checked everything of relevance to the problem and changed the hour counter wheel....I'm pointing to the new one and the old one is just off to the side.

However, if you look at today's picture with the new crystal, the hour counter is still going! The current counter lock part no. 8690  is an ebay replacement I bought after having lost the original, but now that is my prime suspect, so I will have to buy another one. Another suspect is the spring but that seems OK,  so I am going to replace the counter lock to see if that solves the problem.

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Well, I really like the 7750 and will try to acquire another at a decent price. 

JC

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noirrac1j Distinguished Member

noirrac1j

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8 minutes ago, StuartBaker104 said:

Have you read this?

There are a few other suggestions out there too.  Google is your friend!

S

Oh I read it alright! I definitely use Google.

I just messaged a respectable seller (vacheron_nl) about a metal hour counter lock for the valjoux 7750--I've never seen a metal one, only plastic. I am going to have to take the dial off and check the pivot hole but its likely that plastic part. Has anyone ever seen a METAL hour counter lock ETA part 8690?

JC

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