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Delroyb

Heuer Jacky Ickx Eb8420 Teardown

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OK, so my first walkthrough here. More a picture reference for people, who like me, cannot remember for the life of me where things go. Not a particularly nice movement this, a pin pallet chrono, but one in need of a service none the less.

 

Movement comes out through the front of the case. The split stem just needs a good tug to free it. A crystal lift would be needed to get the front of, but in this case it was poor fitting and just fell out.

 

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The split stem

 

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The dial screws, one is a little hidden under one of the chrono levers

 

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The dial comes off, with a little spacer ring

 

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Chrono wheels are held in place by this stamped spring plate. It simply slides backwards for removal. Note how the fingers locate on each staff.

 

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With plate removed, the wheels can be removed.

 

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With the top plate removed, the operating levers can be seen. The small V shaped spring top right is the only thing providing tension on any of the chrono levers. It pinged across the room while I was reassembling. Much swearing and searching ensued. Fortunately a found a subsitute that did the job.

 

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The date mechanism is modular, simply remove the two screws and it lifts out as one. I have to admit I only gave this a cursory clean rather than a full strip.

 

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With the balance out you can see the lovely pin pallet

 

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The click is just a small spring tucked away in here

 

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This plate screw is the location for one of the chrono levers so remember where it goes.

 

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The sub-second wheel needs to be removed from the drive wheel for the chrono

 

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The rest of the going train

 

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And finally the keyless works, which like the rest of the movement are pretty simple

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After cleaning, reassembly was pretty straight forward, though aligning all of the wheels under the one-piece plate was a bit tricky. (And the escapee incabloc spring, I have slotting them back in). One point to note is that, when re seating the chrono second hand, the spring plate needs to be braced agains something otherwise the pinion simply pushes out as you try to attach the hand. Once back together and oiled, time keeping was not too bacd. Not excellent, but then it is a 40 year old pin-pallet which was desinged to be disposable.

 

I could not find a lift angle for the 8420, only the 8422, which I assume to be similar, which is a slightly unusual 60 degrees.

 

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The crappy crystal was replaced with a rather funky bevelled and armoured Seiko item, for reference Heuer Ickx's take a 33mm exactly crystal.

 

post-1299-0-19298100-1438803284_thumb.jp

 

 

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Ahh good ole EB 8420, seem to be popping up more often than not in my servicing circles.... yes that spring is just as important as the balance wheel! - thanks for the tear down..

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Delroy my friend, THAT was a cool walkthrough!

One of the most interesting movements I've seen in a while .... and not being and standard ETA based movements we see day-in day-out, this was a breath of fresh air.

 

Thank you so much for posting it mate, and the pictures were excellent too.

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Tickle me grandmother! I just looked on fleabay and saw the price on these watches!!  :o

 

Was looking to buy one of these for something unusual to restore and wear to work, as I've never seen and pin-n-lever chrono in a wristwatch before ... but after seeing the asking prices I started having chest pains!! :wacko:

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Thanks Lawson. Yes they do command something of a premium because of the heuer branding. The Sears branded ones do not fetch as much and there are a number of other brands that use the 8420 that can be picked up for less than 100 quid.

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I've got 5 of them, sicura ones go for a lot as well as the sornas.. Repaired a few when other watchmakers won't touch them because they take ages to get running relatively well

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Hi there DJT, I simply did all of the jewels with M8000, including the balance jewels, as well as a tiny dab on each of the chrono runners where the spring retainer sits. Then some grease on the keyless works. The way I figured, this was a cheap movement when new, which is probably quite worn in places, so getting carried away with oiling was excessive.

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Hi there DJT, I simply did all of the jewels with M8000, including the balance jewels, as well as a tiny dab on each of the chrono runners where the spring retainer sits. Then some grease on the keyless works. The way I figured, this was a cheap movement when new, which is probably quite worn in places, so getting carried away with oiling was excessive.

Thanks delroyb, I did similar as I couldn't find service /oiling documents. As it's my first pin pallet movement, I just wanted to check there's nowhere I shouldn't be oiling. I used 9010 on the train / balance jewels etc.. & D5 on the barrel arbour, keyless works. Grease on stem, cannon pinion. Is this correct?

3b99934b26f2ad4341cc8390017b1da3.jpgdf1dbb0f2ff6d51baef5a28e6b67729b.jpg2c1aea69ecb6e8ba51504dbbed2903f4.jpg0f555f56327f1a7c5ea0ea87317da28c.jpgf61630899ae781f11ce9d958a992d8ec.jpg0656d4d147b9fc505569df29b5b87b64.jpg0aaed731289311c719da123850429b01.jpg83eb1317d88dd3845c857cbb44b8b602.jpg

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I'd say that sounds pretty much correct. I have to say, they are not the nicest movements in the world to work on, but they appear in (what I think to be) some pretty cool watches.

Agreed, I'm still struggling with timing it though. With the movement facedown I'm getting this fae15162ab1e82b220a005acc556d4dc.jpgbut when I turn it over, it kind of goes all over the place. I'm going to teardown again & re-clean. I've a funny feeling that the hairspring is sticking.

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Agreed, I'm still struggling with timing it though. With the movement facedown I'm getting this fae15162ab1e82b220a005acc556d4dc.jpgbut when I turn it over, it kind of goes all over the place. I'm going to teardown again & re-clean. I've a funny feeling that the hairspring is sticking.

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I serviced a EB8800 a while ago & the issue was two much end shake with the balance. Luckily I found a donor movement that had a tighter fitting balance /staff & the vast difference between DU & DD was resolved.

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I serviced a EB8800 a while ago & the issue was two much end shake with the balance. Luckily I found a donor movement that had a tighter fitting balance /staff & the vast difference between DU & DD was resolved.

Hi clock boy, Unfortunately I don't have a donor movement. Is there anyway I could resolve this with the movement I have?

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I have come across this when stripping a watch. Some repairers put a slip of paper under the rear of the balance bridge which is supposed to tilt the balance jewel down a tiny bit. I have also come across this when the balance staff is a bit tight & it is put under the front of the bridge to lift it a touch. 

The problem is really that EB movements are not the best & most calibers have their pivots not in jewels but set in holes in the bridges. 

With wear over time you get a lot of end & side shake which shows up when on a timing machine. When turning the movement over say from DU to DD you get a sudden show of snow until it settles down.

 In my opinion you can only go so far with these movements. 

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I have come across this when stripping a watch. Some repairers put a slip of paper under the rear of the balance bridge which is supposed to tilt the balance jewel down a tiny bit. I have also come across this when the balance staff is a bit tight & it is put under the front of the bridge to lift it a touch.

The problem is really that EB movements are not the best & most calibers have their pivots not in jewels but set in holes in the bridges.

With wear over time you get a lot of end & side shake which shows up when on a timing machine. When turning the movement over say from DU to DD you get a sudden show of snow until it settles down.

In my opinion you can only go so far with these movements.

Thanks for the reply. It's good to hear it's more of a common problem & not something I've done while assembly. Rather than a complete teardown, I'll concentrate my efforts around the balance. Re-clean the cap jewels & hairspring etc.. Hopefully it may make a difference.

Do you know if it's possible to swap the top cap jewel with the bottom & vice versa. It may be worth a try if it's possible.

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Thanks for the reply. It's good to hear it's more of a common problem & not something I've done while assembly. Rather than a complete teardown, I'll concentrate my efforts around the balance. Re-clean the cap jewels & hairspring etc.. Hopefully it may make a difference.

Do you know if it's possible to swap the top cap jewel with the bottom & vice versa. It may be worth a try if it's possible.

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It is not always possible due to some watch movements have different thickness cap jewels for the top & bottom. As a matter of habit I never swap.

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Thank you Delroy for the very well done walk-through of this Ebauche Bettlach. Did you say this is your first?!? Very well done, then! And extra points (from me anyway) for tackling  not just a jeweled pin-lever, but a chronograph a that. I have many pin levers in my collection, but this particular one I have not worked on. I think these are hard to come by, yes? Congratulations on a job well done. I will certainly use this nicely detailed service pictorial to guide my own pin lever chrono service--whenever that may be.

 

JC

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Thanks Noirrac.  Not my first service, or first chronograph, but my first crack at one of these pin-pallet curios. I suspect that the reason they are hard to come by is the throwaway nature of the movements, meaning once they packed up people probably binned them. Before vintage watch prices went crazy etc (although I suppose at the time they were not really vintage).

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