I had a DayDate with a Shanghai SH3255 v2 movement across my bench recently and since I can't remember ever seeing a tear down of this movement I decided to document my disassembly and make a post about some of the things that I found interesting about the movement.
Before we get started though, I think it's important to note that there are two versions of this movement (hence the "v2" in the name), but in the Comprehensive Guide, I missed the fact that the v1 of this movement appears to use a 31xx style intermediate winding wheel (red circle in the following two images). The 32xx style intermediate winding mechanism has a larger protrusion through the train bridge.
Ok, now let's get on with the disassembly. Here's the movement with the rotor removed. Red arrow points out the larger crown intermediate winding wheel protrusion. Of course the beat and rate adjustor arms also point outwards making it obvious that this is a v2 of the SH3255.
With the automatic bridge removed, we can see that the finishing on this example is quite good. The engraving is good and the perlage is well formed and extends across areas which wouldn't be visible unless you were servicing the watch. I'm not sure if this is how it came from Shanghai factory or if the factory that made this watch did the engraving and finishing (this is a QF watch). While not pictured here, like other 32xx movements from Shanghai, this movement doesn't include the doughnut (donut?) jewel on the bottom automatic bridge for mid arbour support of the winding wheel.
Removing the balance, we can see that while the v2 of these movements don't have the fake hair spring stud decoration plate and do use a real paraflex shock setting, but they don't include a functional end shake adjustment mechanism (red arrow). Indeed, the two brass nuts on the balance bridge posts are free spinning and are purely decorative. If you need to adjust balance end shake on these movements, you'll be doing it with shim washers. Also (as is typical for Shanghai movements) there is no shock setting for the escape wheel (cyan arrow). Also note that this movement (like all Shanghai 32xx movements) doesn't use a gen-spec chronoenergy escapement geometry, so there will be no swapping in gen parts into the balance side (nor likely the dial side) of these movements.
A close up under the microscope of the balance shows how the end shake adjustor screw isn't functional. If it were functional it would have teeth to interact with the functional jack nut on the balance post.
Next we come to removing the dial... There are two sets of dial feet screws on the side of the movement. But it's the screws in the date plate (red arrow) that are the ones used to secure the dial feet of this dial. I'm not sure if gen day date dials use the lip slip fit mechanism that's standard on 3230, 3235, and 3285 movements, but I would suspect so. As such I'd guess that we're getting into non-gen-spec territory here.
With the dial removed this is what things look like. The day disc is held in place by three small tabs which are easy to rotate without any special tools.
With the day disc removed this is what we can see. The date disc is also retained by a single easy to rotate clip.
When removing the date plate from the dial side of the movement it's important to make sure that the day finger (red arrow) isn't positioned over the metal of the date plate otherwise it will hold the plate down even when the three blue screws have been removed. Also note that even though Shanghai used a real paraflex shock setting on the balance bridge, they used a lower cost shock setting for the balance on the mainplate side (cyan arrow).
With the date plate removed we can see a 32xx style motion works design. I suspect that this might not be the case for the VR/SH3255 v1 since that movement likely has a 31xx style keyless works and may use different mechanisms for the motion works as well.
The date plate itself has the day wheel and intermediate day wheel peened into place. These can't be removed during service, so plan on manual cleaning to get any residual oil or dirt out of the tight spaces around these wheels. Once again, it's nice to see perlage in places where it's only going to be visible to somebody working on the movement.
The only other thing that stuck me as worth mentioning during the disassembly was that like the SH3285 this movement also has a removable intermediate winding wheel base. The gen 32xx movements have these parts integrated into the mainplate in a way that they can't be removed. This again speaks to how Shanghai has changed subtle things about this movement from gen-spec while remaining very close to the original design. I wouldn't expect gen parts to work anywhere in this movement unless it's by happy accident.
And here's what the parts trays looked like after bulk disassembly. I'm including these just in case there's something I overlooked and having a picture of what each of the parts looks like (even if it's small) might be helpful.
Before we get started though, I think it's important to note that there are two versions of this movement (hence the "v2" in the name), but in the Comprehensive Guide, I missed the fact that the v1 of this movement appears to use a 31xx style intermediate winding wheel (red circle in the following two images). The 32xx style intermediate winding mechanism has a larger protrusion through the train bridge.
Ok, now let's get on with the disassembly. Here's the movement with the rotor removed. Red arrow points out the larger crown intermediate winding wheel protrusion. Of course the beat and rate adjustor arms also point outwards making it obvious that this is a v2 of the SH3255.
With the automatic bridge removed, we can see that the finishing on this example is quite good. The engraving is good and the perlage is well formed and extends across areas which wouldn't be visible unless you were servicing the watch. I'm not sure if this is how it came from Shanghai factory or if the factory that made this watch did the engraving and finishing (this is a QF watch). While not pictured here, like other 32xx movements from Shanghai, this movement doesn't include the doughnut (donut?) jewel on the bottom automatic bridge for mid arbour support of the winding wheel.
Removing the balance, we can see that while the v2 of these movements don't have the fake hair spring stud decoration plate and do use a real paraflex shock setting, but they don't include a functional end shake adjustment mechanism (red arrow). Indeed, the two brass nuts on the balance bridge posts are free spinning and are purely decorative. If you need to adjust balance end shake on these movements, you'll be doing it with shim washers. Also (as is typical for Shanghai movements) there is no shock setting for the escape wheel (cyan arrow). Also note that this movement (like all Shanghai 32xx movements) doesn't use a gen-spec chronoenergy escapement geometry, so there will be no swapping in gen parts into the balance side (nor likely the dial side) of these movements.
A close up under the microscope of the balance shows how the end shake adjustor screw isn't functional. If it were functional it would have teeth to interact with the functional jack nut on the balance post.
Next we come to removing the dial... There are two sets of dial feet screws on the side of the movement. But it's the screws in the date plate (red arrow) that are the ones used to secure the dial feet of this dial. I'm not sure if gen day date dials use the lip slip fit mechanism that's standard on 3230, 3235, and 3285 movements, but I would suspect so. As such I'd guess that we're getting into non-gen-spec territory here.
With the dial removed this is what things look like. The day disc is held in place by three small tabs which are easy to rotate without any special tools.
With the day disc removed this is what we can see. The date disc is also retained by a single easy to rotate clip.
When removing the date plate from the dial side of the movement it's important to make sure that the day finger (red arrow) isn't positioned over the metal of the date plate otherwise it will hold the plate down even when the three blue screws have been removed. Also note that even though Shanghai used a real paraflex shock setting on the balance bridge, they used a lower cost shock setting for the balance on the mainplate side (cyan arrow).
With the date plate removed we can see a 32xx style motion works design. I suspect that this might not be the case for the VR/SH3255 v1 since that movement likely has a 31xx style keyless works and may use different mechanisms for the motion works as well.
The date plate itself has the day wheel and intermediate day wheel peened into place. These can't be removed during service, so plan on manual cleaning to get any residual oil or dirt out of the tight spaces around these wheels. Once again, it's nice to see perlage in places where it's only going to be visible to somebody working on the movement.
The only other thing that stuck me as worth mentioning during the disassembly was that like the SH3285 this movement also has a removable intermediate winding wheel base. The gen 32xx movements have these parts integrated into the mainplate in a way that they can't be removed. This again speaks to how Shanghai has changed subtle things about this movement from gen-spec while remaining very close to the original design. I wouldn't expect gen parts to work anywhere in this movement unless it's by happy accident.
And here's what the parts trays looked like after bulk disassembly. I'm including these just in case there's something I overlooked and having a picture of what each of the parts looks like (even if it's small) might be helpful.
