[zenciti]

Hi all,

I have a 7S36 from 2005, last serviced and timed in August 2019.
Ran ok for a year or so then these symptoms began to appear:

Runs within +/- 5 spd when fully wound, slows to about -25 spd after 24hrs, then -200 spd 16 hrs later.
The power reserve remains good - the watch runs for close to 40hrs from a full wind.

Pretty certain it is not the escapement that is the issue and I'm thinking it's the barrel and/or mainspring.

Before I open it up and have a look, any help and advice would be much appreciated.

Thanks in advance.

 

[7s26b]

Definitely needs a good service, something is dragging on the train enough to produce - delta, where it's normally +.
I don't think nearly 40 hrs duration is enough on a 7s36, should be mid 40's, IMO

 

[nzwatchdoctor]

Definitely needs a good service, something is dragging on the train enough to produce - delta, where it's normally +.
I don't think nearly 40 hrs duration is enough on a 7s36, should be mid 40's, IMO

Agreed.
Take the balance and pallets out and see if the escape wheel has recoil when at the end of it's free running power.

 

[Grammarofdesign]

I always thought that as the mainspring ran down the watch ran faster due to lower resistance in the gear train when things are tight and meshed properly. So that makes me think a rotating wheel/gear is too loose so then it really becomes a matter of power being reduced as it winds down.

 

[rileynp]

How wide is the regulator pins’ gap?

 

[zenciti]

Thanks for your inputs guys... will have to check on the regulator pin gap when I have the time to open it up.

Another anomaly is that the amplitude also drops when the watch slows, from a decent 250 when fully-wound to 150 or less 24-36 hrs later.

 

[zenciti]

How wide is the regulator pins’ gap?

Finally got the time to open the watch up and the regulator pins look nice and straight with the hairspring resting lightly on the inner pin...

What would i be looking for if this was the cause of the poor timing?

 

[rileynp]

If your gap is less than 1.5 times the width of the hairspring, then this likely wouldn’t be the cause. With the information available to me currently, I’m afraid I don’t have any other guesses.

 

[tritto]

I've been following a thread discussing a very similar symptoms experience but owners of the Rolex 32xx calibers. Good timekeeping when fully wound and no decrease in power reserve. However the amplitude drops as the power reserve goes down and the rate falls (contrary to expectations that the rate increases as the amplitude drops).
The cause of the problem is apparently excessive wear in some element of the gear train (those that know precisely where aren't saying), leading to friction and then to the symptoms described. Your 7S36 is in good company.

Naturally most of the Rolex owners have no idea how their watches work. There is one camp that believes there is a systemic fault with the family of movements and another that believes that Rolex is faultless. The long running thread periodically devolves onto **** slinging.

 

[nzwatchdoctor]

I've been following a thread discussing a very similar symptoms experience but owners of the Rolex 32xx calibers. Good timekeeping when fully wound and no decrease in power reserve. However the amplitude drops as the power reserve goes down and the rate falls (contrary to expectations that the rate increases as the amplitude drops).
The cause of the problem is apparently excessive wear in some element of the gear train (those that know precisely where aren't saying), leading to friction and then to the symptoms described. Your 7S36 is in good company.

Naturally most of the Rolex owners have no idea how their watches work. There is one camp that believes there is a systemic fault with the family of movements and another that believes that Rolex is faultless. The long running thread periodically devolves onto **** slinging.

There is a third or forth wheel in Rolex 31xx movements that the pivots wear prematurely - bad hardening job by Rolex. There is a generic replacement that is much better and very cheap.

 

[7s26b]

Time to whip out the barrel and have a look see, like you initially thought.

 

[tritto]

Curious to see that a very mildly offensive phrase I used above, starting with an S and ending with a T has been ****'d out. Was that a mod or forum software?


Sent from my iPhone using Tapatalk

 

[7s26b]

Curious to see that a very mildly offensive phrase I used above, starting with an S and ending with a T has been ****'d out. Was that a mod or forum software?


Sent from my iPhone using Tapatalk

Did you say ****? maybe shite would work??💩💩💩😂

 

[zenciti]

Barrel duly opened... mainspring, arbor and barrel itself cleaned and re-lubricated but symptoms persisted so on to next step - clean and oil balance shock setting jewels.

Initial signs are good after a bit of tweaking on the timegrapher... getting consistent +5 spd, 220+ amplitude and 0.0ms beat error fully wound.

Next 24-36 hrs will tell if the issue is sorted.

 

[zenciti]

Just to update that after plenty of trial and error I finally traced the problem to the pallet... for some reason both pallet stones were loose.
The resulting play when the pallet engaged the escape wheel did not affect the movement when fully wound, but when the power reserve diminished, it caused the watch to run slower and slower with poor amplitude.