This watch exploded during service! (1970 Bulova Sea King "Crosshair Camaro")

My good friend @OmegaMan75 recently got a vintage 70's Bulova Sea King with a very slick-looking TAG Camaro-style case! He reached out to me when he got the watch, saying that that watch hands weren't moving at all despite it looking in near-pristine condition.

It's usually a loose cannon pinion that can cause this issue in a watch, but little did I know that not all movements are built the same.

Movement looked great when I started the disassembly. I didn't see any service marks in the case back but I did see some dust and hairline scratches near the regulator arm. This watch was previously serviced since the plastic shock ring was glued back together.

Upon reaching the cannon pinion, I was very surprised to see that there was nothing wrong with it! It wasn't a friction-fit type, but was spring-fit by another wheel. I started to see a line of wheels that led me to the culprit: A second cannon pinion on the driving wheel!

Removing this pinion from the driving wheel was a nerve-wracking experience. Before I started servicing this movement, I read as much info as I can on why they went with this design. Having an indirect pinion gives way to a larger balance for better accuracy, and slimmer profile on the movement.

That unfortunately, doesn't make my service job any easier😭

Seeing that lanterning point was a good sign where I should apply pressure so that it friction-fits back onto the driving wheel.

What can possibly go wrong?

After the slightest pressure from a modified nipper, the cannon pinion exploded! I've successfully repaired pinions before, but having shrapnel almost hitting my unprotected eye was a first.

I'd usually stop at this point out of sheer frustration, but after repairing enough watches, you just suck it up and keep going with the disassembly.

I took a break from repairing this movement until the replacement part arrived.

It was a relief to know that the pinion I broke was likely a flawed, early design. The replacement driving wheel had a beefier pinion profile that looked more robust.

This movement also had some funky parts; like these LEGO-style "Breguet Springs" that 'hold' the reversing wheels on the automatic winding works.

Oiling jewels can still be a challenging task, but this one luckily went smoothly. Losing a jewel is never fun!

Assembly almost went without a hitch. The calendar plate screws have the same brittleness as the pinion I tried to restore, but everything else worked properly. Also did the extra work removing dust and scratches on the dial and crystal.

This one cleaned up very nice! Got it to -3/+6 seconds a day above 250° amplitude. A very healthy piece, and I'm glad to see this keep excellent time again!

Thank you to @OmegaMan75 for trusting me with this repair job. Every watch I repair has its own unique challenges, but its always worth the effort seeing a watch owner smile 😀