Certina automatic movement (25-651) winds heavy after service

[Gaus]

Good evening watch friends, I have serviced a Certina (blue ribbon) 25-651 automatic movement. After service the watch runs very nice, but winding by hand is very heavy. What can cause this problem. Thank you all in advance for any suggestions. With kind regards, Hans 

[Jon]

At what point does the winding become stiff, crunchy, resistant, etc? Does it feel like this when there is no power in the movement, or after you get to half way would, full wind? How doe the mainspring feel when it slips on the barrel wall? What breaking grease did you use? Did you try what it was like to wind before the automatic module was fitted? When you fitted the keyless work, did you observe the winding pinion, clutch and yoke? Was there any sloppy movement of those parts, especially the winding pinion that may have worn a larger slot, therefore it finds it hard to engage with the crown wheel because of the movement and it feels tight and crunchy, or close to fu7ll wind the clutch slips against the winding pinion because of the slop or an underpowered yoke spring. There are many thing that could be problematic. It's best to give us some pics and a more detailed background to the movement. what was it like before it was serviced, etc?

[nevenbekriev]

The typical reason for stiff winding (when no wear or defects of the parts) is not proper lubrication of the reverse wheels

[Jon]

Strangely enough, this topic was covered in the lesson when assembling the Valjoux/ETA 7750 on Monday night.

[Gaus]

Hello, thanks for the response. I used Moebius 8217 for the barrel wall and Lubeta for the reverse wheels. The winding pinion and clutch where oké. I re-used the mainspring because it looked oké to. After three or four days in the watchwinder the watch runs nice. 

I'll try the winding without the automatic module. 

[VWatchie]

On 8/2/2024 at 3:10 PM, Jon said:

Strangely enough, this topic was covered in the lesson when assembling the Valjoux/ETA 7750 on Monday night.

I'm just curious (as I have V105). Would you oil just one of the protrusions or all of them? I think I see three protrusions in the picture.

[Jon]

4 hours ago, VWatchie said:

I'm just curious (as I have V105). Would you oil just one of the protrusions or all of them? I think I see three protrusions in the picture.

I would just oil two of them opposite from each other, but that's just what I do. Some might do more.

On a side note I use V105 for rotor bearings as well and don't buy into using V106. Just more money for pretty much the same stuff.

If you don't have V105 for the bearing, a small drop of 9010 on just one of the ball bearings, unless they're ceramic bearings that don't need to get lubricated at all

[VWatchie]

1 hour ago, Jon said:

On a side note I use V105 for rotor bearings as well and don't buy into using V106.

This is the first time I’ve heard of that. Do you remove the rotor bearing or do you apply V105 directly to it? Because we don’t want to get V105 on the rotor itself, right!?

[mikepilk]

As pointed out above, it's usually the reverser wheels. I've had this problem, and re-cleaning the wheels has fixed it.  Or they could just be too worn

[Jon]

4 hours ago, VWatchie said:

This is the first time I’ve heard of that. Do you remove the rotor bearing or do you apply V105 directly to it? Because we don’t want to get V105 on the rotor itself, right!?

If it is a bolt type rotor bearing like in a modern ETA 7750 I would remove the bearing and dip it in. If it is a friction fit type, like on an old Valjoux 7750 then I use a pipette to put a very small drop on the bearing without getting on the rotor, because it will leave a bit of a waxy white mark otherwise. Try it, works a treat!

 

3 hours ago, mikepilk said:

it's usually the reverser wheels. I've had this problem, and re-cleaning the wheels has fixed it.  Or they could just be too worn

If a client brings in an automatic that hasn't been service in 8 or 9 years plus, I replace the reversing wheel(s) as standard

[mikepilk]

4 hours ago, Jon said:

If a client brings in an automatic that hasn't been service in 8 or 9 years plus, I replace the reversing wheel(s) as standard

That's a sensible policy, if the wheels are available, but they are becoming hard/impossible to find.