The introduction of the Tudor Pelagos (and the Black Bay) at Baselworld in 2012 reinforced Tudors ability to get the styling of their watches spot on. Whilst the Black bay was undoubtably inspired by the vintage Tudor divers of the 50’s and 60’s the Pelagos was much more up to date with it’s titanium case, 500m depth rating with just a nod to the traditional with it’s snowflake hands. Both watches were instant successes with people clamouring for both models in equal measures. The original Pelagos is powered by a slightly breathed on and decorated ETA2824-2, the new Pelagos which was introduced at this years Baselworld has an in house movement, the MT5612. This is hardly surprising with Swatch Group controversially cutting off the supply of ETA movements to manufacturers and parts to independent repairers (me!) at the end of this year. This Pelagos came in with an interesting problem, when manually wound the spring made a loud slipping noise almost as though the spring was broken near the barrel wall.

Whilst the case is manufactured from lightweight titanium, the caseback appears to be made from stainless steel judging by the weight.

With the back removed the ETA 2824-2 movement can be seen in all it’s glory. There’s a lot of finishing work that’s been applied to the plates and bridges in the form of perlage and Geneva stripes.

The first job is to remove the signed oscillating weight, this gives a clear view of the autowind mechanism which is the next thing to be removed.

Here’s a view of the underside of the autowind plate, the two wheels to the right of the picture are the reverser wheels. These convert the motion of the oscillating weight into constant winding of the mainspring, regardless of the whether the weight is rotating clockwise or anticlockwise.

The movement is then uncased and the dial and handset is removed.

With the dial removed work can start on stripping this side.

I removed the date disk first….

….then proceeded to strip the calendar work….

….and finally the keyless work.

The watch was turned over and I started with the barrel bridge and barrel.

The balance work was next to go.

Finally the bridges and wheel trains came off.

This meant all the components were now ready for cleaning and inspection.

I was expecting a broken maispring in this watch but when I removed it it actually looked to be in good shape, as did the arbor and barrel. The mainspring was replaced anyway as there was obviously a fault in that area causing the slipping.

The rebuild continued with the barrel and second wheel.

The bridge and wheel train were next to be refitted.

The balance was fitted and some power applied which allowed the rough adjustment of the beat and regulation.

The regulator and beat lever on these Tudors are linked together and the adjustment between them is carried out by rotating the worm screw on the beat lever. The balance bottom jewel is ready to be fitted in this picture.

The movement was turned over and assembly continued….

….until I could refit the dial and hands.

The movement was recased….

….and the autowind mechanism and oscillating weight were refitted.

The watch was then fully wound and placed on the final test machine. After four days of checking and a couple of small adjustments it was ready to go back to the customer. I gave it a final wind and lo and behold I heard that damn spring slipping again! The only other culprit is a worn barrel wall but when I’d inspected it the surface looked great and the scallops were well defined. I wondered if a stronger braking grease would sort out the slipping so I ordered some Mobius 8213 which offers a strong braking effect, but I also ordered a replacement complete barrel just in case! When the parts arrived I stripped the barrel, cleaned it and the mainspring thoroughly and applied the 8213 grease.

Once reassembled the slipping was still there so it was stripped once more and the barrel changed for the new one.

Unsurprisingly this had the desired effect and the noisy slipping was no more! The watch was closed up tightly with a smattering of silicone grease on the o-ring surfaces to make it ready for a leak test.

The watch passed this without issue and was now ready to go back to the owner. The barrel problem had me scratching my head a for a bit but it just goes to show that even when parts look fine during inspection it only takes an imperceptible imperfection to cause a big problem. I think you’ll agree the Pelagos is a very purposeful looking watch, I like it a lot!