Benrus: Sky Chief: Cal.Vaijoux72
Symptoms: Overhaul for store-bought products
Repair details: Overhaul
Repair cost: 33,000 yen (reference price)
This is a Benrus military watch, Sky Chief. This is an overhaul of a store-bought product. The condition is that the accuracy is unstable, the movement is dirty, and the oil is gone.
I disassembled it and cleaned it. The 72R mark on it stands for Valjoux 72.
This is the lever that operates the chronograph. It has some rust and dirt.
I removed the rust and added a hairline. I did the same for the other parts and assembled them in a clean state. It doesn't affect the accuracy or operation, but I'll do it as much as I can.
I even assembled the time mechanism.
This is just the initial assembly, so the precision is not yet achieved. It will progress considerably, so we will adjust the precision.
Before disassembly, I had moved the regulator all the way to the retarding position, but it was still moving forward, so I changed the weight of the balance wheel (a weight-like structure that improves accuracy).
Chiraza
It's very small so it's hard to see, but there is a round washer in the center. Adding or subtracting this changes the weight. If it's heavy, it will lag behind, and if it's light, it will move forward. Of course, the weight is not the only factor, so we will adjust it while looking at other parts as well.
I assembled it. Since it is a model from the 1940s or 1950s, it does not have a shock-resistant mechanism. If it is dropped or subjected to shock, the part called the top core may break, so care must be taken.
After the running test, the product is ready to be put on display in the store. It is clean and tidy compared to the condition before the overhaul.
This is a model with a low circulation and it is difficult to gauge the market price, but it is a military watch and a chronograph equipped with a Valjoux 72, so I think it is a low price. Please check out our online store .