On My Bench - Tudor Submariner 7928

It was in a burst of innocent ignorance that I said OK to a member who asked if I'd be willing to give one of his favourite Submariners a service.

"Sure, no probs mate, just send it down!" I said, and a day or so later a nice vintage Subbie arrived. I had a quick look, took down the model and serial numbers for my records and put it in the safe as I was still working on the Seiko.

Anyway, I finished the Seiko a few days ago and set it aside to keep an eye on time keeping and do occasional chrono testing.

That's when I decided to do some research on the movement in the 7928 and found out it was a Tudor 390.

A Tudor 390!
Apparently just the mention of the caliber is enough to make seasoned watchmakers go "Oh! What's that behind you?", and then when you turn back, POOF!. They've vanished as if they were never there.

That's when I figured I'd got in over my head, some of the comments on the interwebs pointed to the problems with getting parts, problems with the COST of parts if you did get lucky, problems with the lack of information on the caliber etc etc etc etc. I couldn't actually find anyone who had a single nice thing to say about the poor 390.

I thought long and hard about it, read up as much as I could, and as most of the information I could find suggested that I had just stepped on something that went "click............", I decided to consult "A Wise One".

The Wise One (actually @Archer 😁) got back to me with some excellent support material, a good discussion on lubrication and servicing, and ominously, some wise words.

His wise words did not quite fill my cup of confidence:

"The Tudor 390 is widely known to be a problematic movement to service, even for trained watchmakers"

"the best comparison I can see is the old Rolex Cal. 1030, and having done some of those if it's in any way similar, these are not for the faint of heart"

"Knowing what not to take on is one of the most important things you can learn in this business..."

So, a sensible adult, who happens to be an expert in this field, had given me a very good idea of what was ahead.

Hmmmmmmm, what next?

I PM'd the owner and gave him the good news, and like a man who has great trust in his proctologist, his response was, to quote:

"If you can fix bombs and stuff this is a walk in the park.......seriously, I have faith in you mate, give it a go"

And that's how we got to be where we are at the moment.

You're all probably bored shiftless by now, so time for some pics.

As you can see, essentially a Rolex Submariner with a differently marked dial, and a different movement.



With the caseback off, we can see it dates to 11/67, so assuming it came together on 23/11/1967, its 52nd birthday is TODAY!
The caseback bears numerous service marks, and while sometimes this is a good thing, it all depends on who did the servicing.



The Caliber 390 (shudder), shows signs of having been serviced by watchmakers who were in a hurry to move it on, or a gorilla with a cold chisel. There are some unusual dings and gouges that I wouldn't expect to see on something that should be treated with kid gloves.



I don't mind the wear marks on the lugs, it means that the watch was worn on a bracelet for a long time. What I do mind is the gouge on the rotor. What hapenned there? The gouges in the case ring near the casing screws 😵‍💫, evidence of the use of oversize screwdrivers 😡.



Oh well, enough bitching about it.

I'm going to get myself a beer, sit myself down, and think about what I've let myself in for.

I think it's beginning to dawn on me why this movement has gained the reputation it has.

🤨

Derived from the base caliber, a Fluerier 350, it appears that the design of the autowind mechanism was done in a totally seperate studio with no discussion with the designers of the original caliber, and no consideration for future watchmakers who would have to work on it.

While the movement is rather easy to strip down (see this video that Al found for me), getting some of it back together has some tricks for young players (and old ones judging by some of the battle scars on the plates).

The autowind mechanism has its own bridge to which the rotor and reverser wheel assemblies are mounted. Easily removed as per the video.

BUT!

When you come to fit the auto system, you have to fit the rotor to the bridge first, then fit the axle pin from "below" and then fit the axle pin cross clip from "above". You then have to jiggle the rotor bridge complete with rotor onto the base caliber while aligning the winding wheels and locating pins and screw holes.

Well, that's my take on it, more to come.

And a photo to keep you interested.



Rotor bridge with reverser wheels, rotor axle pin and rotor pinion.

OK, change of plan.

I'm going to do the autowind movement, finish it and set it aside before doing the base caliber.

So the tasks are:

1. Strip, Clean, Inspect, Lubricate and re-assemble the Autowind system (finished today).
2. Strip, Clean, Inspect, Lubricate and re-assemble the base caliber.
3. Strip, Clean, Inspect, Lubricate and re-assemble the Case/Bezel.
4. Assemble and test the complete movement.
5. Clean the dial and re-lume the dial and hands.
6. Fit the movement to the case and test functions.
7. Timing/Regulating.



(Don't panic Geoff, just joking about Step 5 - 😁)