Source for 116710LN GMT II CASE to fit 3186

[freddy333]

Anyone know of a source for an accurate CASE (or rep with accurate CASE) to fit a gen 3186 spec movement?

Need properly aligned rehaut engraving  -- so ROLEXROLEXROLEX letters align with minute marks on gen dial.
Thanks in advance.

[freddy333]

 Update --

After exhausting all the usual sources for accurate 116710LN cases, I turned to Andrew (trustytime) & took his advice (which I have always found to be reliable) & purchased 1 of his superclone 116710LNs to use as a case donor. Anyone following a similar upgrade path should be aware that the 116710 has had 2 movements -- 3186 & 3285 -- the 3186 was discontinued in 2018 & replaced by the 3285 (main improvement is an increased, 72 hour power reserve versus the previous movement's 48 hour reserve). Therefore, all of the LNs should have been fitted with the 3186 & all recent GMTII models will be powered by the 3285. Unfortunately, my Rolex parts book predates either movement, so I cannot say with certainty what, if any, parts these 2 movements share, but I doubt there are many because the 2 movements look very different.


Although the use of a complete clone watch is a very inefficient use of capital for a franken project, it is alot less costly than sourcing a gen case, which are nearly as rare as gen 14k Newman Daytonas. Most of the upgrades & overall process is similar to what I previously detailed in my Big Kahuna Daytona clone project, with the exception of the additional requirement of a clone case since the Big Kahuna was based on a clone (which came with an accurate 'clone' case) & this project is based on an old rep (which came with a good, but not 100% accurate case). Because everything that you can see, feel & operate on the final watch will be gen, it makes no sense to house it all within a 'good, but not 100% accurate case'.

 

What began life as a correct hand stack (CHS) ETA-powered rep purchased many years ago is morphing into a super-clone.

Years ago, I upgraded the watch with --

- gen xtal

- gen crown/tube

 

Recently, I swapped the ETA for an Asian 3186 clone (my experience with 4 clones has been consistent -- all met or exceeded Rolex/COSC timing specs out of the box & have maintained those specs)

Currently, awaiting these incoming parts --
- Andrew's 116710LN clone (case donor)
- gen dial

- gen handset

- gen auto-wind components (eg reverser wheels)

- gen signed bridges

- gen rotor

- gen balance/bridge

- various gen & Swiss-made screws to replace poor quality/damaged clone screws
&, to do the final project the justice it will deserve, I will be replacing the solid steel caseback with a German-made display caseback, which is superior -- appears to be similar quality, but offers a slightly larger display area -- to both the Big Kahuna's ebay-sourced display caseback & Rolex's own 116506 display caseback.

[oldtools]

I look forward to seeing your build

[freddy333]

I should have parts within the next 2 weeks & will post pics of the completed watch shortly after that.

[freddy333]

UPDATE  --

 

For those who have not been following the frustrating & near daily trials & tribulations of this build on RWI, the work has been painfully slow, but is nearly complete.

2 items remain on my to-do list --
 

1. The bezel insert in the pic is just sitting loose in the bezel channel. On this particular 'clone', the insert is held in with a ring of adhesive instead of being pressed into the bezel like the gen. I am awaiting the bezel adhesive ring, which should be here by tomorrow or Friday.

I would have preferred a press-fit insert, but since there is no difference in the external appearance & pressing these ceramic inserts is a risky (ie, expensive to replace when they crack) proposition, I can live with it.

2. For some reason, unlike the 1165xx Daytona clones I have worked on, although the gen balance/bridge fits perfectly, it does not function properly in these 3186 'clone' movements. I think the balance rim may be coming into contact with the main plate, which suggests that either the gen balance staff pivots are shorter than the 'clone' pivots, or the cap jewels are positioned differently, or the pallets or pallet stones may be oriented differently. So, for now at least, I will not be able to install the display caseback since the lack of a free-sprung balance is a dead-give-away. My plan is to disassemble my original 3186 'clone', fit only the balance to the main plate & see where the problem lies -- & fix it.

 

But with all of the externally visible gen parts installed, this thing definitely looks & feels the part. In addition to eliminating the very minor tells that existed in my original ETA-powered 116710LN franken (a few months ago, I swapped the ETA for a generic '3186' I sourced on ebay that mostly fit), it also feels a bit weightier & more solid. I am not quite sure what is causing the greater solidity, but it is definitely something you can feel when holding or wearing this watch.

Like the Big Kahuna, even out of the box, Andrew's GMT is quite wearable with a degree of confidence. Where the out-of-the-box 'clone' falls short is the AR coating on the cyclops, which is described as 'With light AR on Cyclops like Genuine'. I do not see it. Having done a bit of research & experimentation on this subject a dozen or more years ago (there is a thread or 2 on RWG if you care to spend the time to search this forum), if there is AR on the cyclops, it is insufficient to create that very identifiable (from across the room) 'black hole effect' over the date that gen crystals are known when light hits the entire crystal -- & that unmistakable rainbow you see in normal (non-reflecting) light (see pic below of my watch with gen crystal installed).

 

Also, like the Big Kahuna, because this is the original style of 116710 with the plain black bezel insert, it is no longer 1 of today's IT watches. So I think most who see it in the wild assume it must be gen because those original ceramic GMTs are now several years old & no longer a fixation of youtubers, flippers & grey marketeers.

After the bezel insert has been properly installed, I will post some wristies of the finished watch.