Omega Genève (166.041 cal.565), rattling seconds hand

[swiss2k]

Hello everyone,  

 

Recently I have noticed the second hand on my Omega Genève is kind of falling behind and then quickly jumps forward, rattles, does not keep up with the Tik and the Tak (pretty sure there is a greater way of describing that, but I do not know it). 

My first thought was that maybe something is blocking, but the movement keeps time perfectly (0-1s/d). So that is out of the question. Beat error? Well no its perfect.  

So, I took off the automatic winding and looked at the second pinion, and what I discovered is that there is quite some play between the teeth of second pinion and second wheel. Basically, the wheel bumps the pinion rather than staying in contact all the time.  

Would adding some oil, on the second pinion under the pressure plate, to smooth the movement, do the deal? Or are there any other options?  

 

Thank you in advance! 

[mikepilk]

What is the movement ?  I have a few 1### series where I have had the same problem. (It's definitely nothing to do with beat error - which doesn't cause any problems unless it is huge)

The teeth look fine to me. The spring is there to prevent the jerky movement caused by play in the teeth. 

The spring tension needs to be just right, too tight and it kills amplitude. Too slack and it doesn't do it's job of preventing jerkiness.

I put a tiny amount of oil on the tip of the second hand pinion.  I have a Technical Sheet for the 1### series which shows that the friction spring should be lubricated. 

[swiss2k]

Hi @mikepilk, thank you for the reply. 

Movement Omega 565. 

I will try to add more tension with the spring. And I also added a bit of oil. I would assume that actually the oil should smooth out the movement of the hand. But how thick should the oil be? 

[mikepilk]

1 hour ago, swiss2k said:

Hi @mikepilk, thank you for the reply. 

Movement Omega 565. 

I will try to add more tension with the spring. And I also added a bit of oil. I would assume that actually the oil should smooth out the movement of the hand. But how thick should the oil be? 

Make sure that there is some tension there, but before adjusting it (it's easy to break those springs) I'd try the oil.

Second pinions are oiled with thin oil, 9010, so as not to effect amplitude, so that's what I use.

[gbyleveldt]

I did one of these just the other day with a similar issue; that spring lever holding down the seconds pinion can be bent, thus losing tension, when the second hand is fitted without supporting that spring. On those movements you should use a staking set to fit the second hand, or provide a means of support under that spring when fitting the hand

Edited October 7, 2022 by gbyleveldt