Service: Bulova Sea King with Bulova 11AC Movement

 In Watchmaking

Another Bulova with an in-house 11AC movement on the bench. I restored a Bulova with the same movement before that was only one year younger.

This particular model is a Bulova Sea King and the date code on the back (L6) dates it to 1956.

The watch did run but winding the watch and setting the time was difficult. It was also a couple of minutes fast per day.

Here we go!

Disassembly

Before you start working on a mechanical movement, make sure to remove all the power from the mainspring. This method will prevent any damage while working on the wheel train.

Move the click away from the ratchet wheel while letting the crown slip between your thumb and index finger.

When all power has been removed, you can safely lift the balance and the pallet fork.

Bulova dress watch with Bulova 11AC movement

The balance and the pallet fork with the pallet cock removed. It’s obvious that the entire movement is slightly greasy.

Flip the movement around to lift the cannon pinion. If you don’t you can’t lift the center wheel when you’re working on the wheel train.

Remove the ratchet wheel and the crown wheel. The crown wheel has a left-handed screw.

Bulova dress watch with Bulova 11AC movement

The crown wheel and the ratchet wheel removed. Look at the caked grease around the barrel arbor.

Lift the barrel bridge.

Bulova dress watch with Bulova 11AC movement

The barrel bridge removed.

Always open the barrel to check the condition of the arbor and the mainspring. It’s been a while that I’ve seen a barrel that was as dirty as this one.

This causes swings in amplitude which is one of the reasons it doesn’t keep accurate time. It also causes the power reserve to drop.

I removed the mainspring and ordered a new one. Make sure to pre-clean parts like this as much as possible with a peg wood, cocktail stick, or an old toothbrush. If you don’t do that, the cleaning machine might not get it all and your cleaning fluids will go bad very quickly.

Bulova Sea King with Bulova 11AC movement

Lift the wheel-train bridge to gain excess to the wheel train.

Bulova dress watch with Bulova 11AC movement

The wheel-train bridge removed to expose the wheel train.

Lift the escape wheel, the fourth wheel, the third wheel, and the center wheel.

Bulova dress watch with Bulova 11AC movement

The top plate empty. The hardened grease is also visible on the inside of the barrel arbor hole.

Flip the movement around.

Lift the set lever spring, the return bar with its spring, the setting wheel, and the minute wheel.

Remove the set lever screw so you can take out the winding stem with the crown wheel and the castle wheel.

Bulova dress watch with Bulova 11AC movement

The bottom plate empty.

Pre-clean the pivot holes and bearing jewels with a peg wood. Clean all the parts in the watch cleaning machine.

Bulova Sea King with Bulova 11AC movement

There’s a lot of wrist cheese on the inside of the crown. This makes it difficult to wind the watch and set the time.

Assembly

Start with the main barrel and the wheel train.

Bulova Sea King with Bulova 11AC movement

Reinstall the wheel-train bridge.

Bulova Sea King with Bulova 11AC movement

Install the barrel bridge, the crown wheel, and the ratchet wheel.

Bulova Sea King with Bulova 11AC movement

Turn the movement around and start with the motion works and the keyless works.

Bulova Sea King with 11AC movement

Flip the movement to the top plate and reinstall the pallets and the balance.

After recasing it, I noticed that the hands were floating too high above the dial.

There are many movements that exist in different configurations to fit certain dials and hands.

I pulled a shorter cannon pinion and hour wheel from one of my donor movements.

Bulova Sea King with Bulova 11AC movement

What do you think of this Bulova Sea King? Do you have a similar one or would you like to add one to your collection? Let me know in the comments below.

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