Drag in day/date mechanism, Timex 27 movement

[RichJensen]

I'm working on a Timex 27 movement (24 with day & date).

The base movement ran fine with a good cleaning/oiling. However, with the day & date rings attached, it hangs when doing the day/date changeover--if the movement is sitting face up.

When the movement is inverted, it handles the day/date changeover properly.

I've oiled/greased per page 4 of the Timex service manual for the movement.

Thoughts/suggestions??

[Plato]

2 hours ago, RichJensen said:

I'm working on a Timex 27 movement (24 with day & date).

The base movement ran fine with a good cleaning/oiling. However, with the day & date rings attached, it hangs when doing the day/date changeover--if the movement is sitting face up.

When the movement is inverted, it handles the day/date changeover properly.

I've oiled/greased per page 4 of the Timex service manual for the movement.

Thoughts/suggestions??

Loose cannon pinion.

[HectorLooi]

I don't think it's a loose cannon pinion. If it were so, it would stop regardless of whether it's dial up or dial down.

How was the movement cleaned? Was a full disassembly done or the "dunk and swish" method used?

Was the hairspring unpinned and the balance wheel removed?

[Nucejoe]

 So face up you get less torgue out of the oscilator, which indicates an issue with pivot at the cock side or dried oil in the setting.

 How sure are you the cock jewel setting is adequately clean?  you can still have congealed oil there, I would drop a bit of naphta on the setting, it will find its way inside the setting and temporarily softens any old oil that might be there.

Another possibility is faulty pivot, which should be examined under high magnification.

In case of excessive end shake, the other pivot end if faulty can cause the problem. 

[JerseyMo]

it could be an issue with the parts on the dial rest.  Here is a 'test' m27 built by Timex I have in my collection. Notice the cut out that allowed for viewing of the internal parts.   It could be a fatigued detent spring. 

[RichJensen]

On 8/12/2021 at 3:55 AM, HectorLooi said:

I don't think it's a loose cannon pinion. If it were so, it would stop regardless of whether it's dial up or dial down.

How was the movement cleaned? Was a full disassembly done or the "dunk and swish" method used?

Was the hairspring unpinned and the balance wheel removed?

It was the 'dunk and swish' method. There was a fair bit of dried grease that needed a couple baths in Dawn followed by a rinse and then naptha to work loose.

I have had several, shall we say, unfortunate outcomes when I've unpinned the hairspring & removed the balance wheel on these Timex movements. I've worked my way up to being able to remove the V-conic screw & oil the balance wheel staff that way, but I'm going to need a lot more practice before I feel comfortable removing the balance on a movement that I actually want to work again.

On 8/12/2021 at 4:03 AM, Nucejoe said:

 So face up you get less torgue out of the oscilator, which indicates an issue with pivot at the cock side or dried oil in the setting.

 How sure are you the cock jewel setting is adequately clean?  you can still have congealed oil there, I would drop a bit of naphta on the setting, it will find its way inside the setting and temporarily softens any old oil that might be there.

Another possibility is faulty pivot, which should be examined under high magnification.

In case of excessive end shake, the other pivot end if faulty can cause the problem. 

As part of the troubleshooting process, I've given extra attention to the index wheel.

The problem as it reveals itself is that the movement will run for maybe two minutes (I did not time it exactly) before hitting something that causes too much drag, causing it to slow and stop.

Thanks, both of you, for your advice & help.

 

[RichJensen]

On 8/11/2021 at 2:25 PM, Plato said:

Loose cannon pinion.

Unlike the basic 24 movement, these day/date models have a plate over the hour wheel (I think that's the correct term?) & cannon pinion, so they can't really float.

I did, however, add a bit more oil to the hour wheel & cannon pinion when I had it partially disassembled.

[RichJensen]

On 8/12/2021 at 8:41 AM, JerseyMo said:

it could be an issue with the parts on the dial rest.  Here is a 'test' m27 built by Timex I have in my collection. Notice the cut out that allowed for viewing of the internal parts.   It could be a fatigued detent spring. 

That's pretty cool.

One of the things I did later on Wednesday was thoroughly oil and grease the day/date change wheel and the spring.

The spring itself seems to work properly when manually setting the time. I get a distinct 'click' and the date change is, honestly, quite a bit faster than some of the cheap quartz movements that use plastic springs.

After doing some additional oiling/greasing, the movement ran through the day/date change face up at about a 30 degree angle.

After a bit more  attention to the day/date wheel & spring, the movement wouldn't run through the day/date change from any position.

 

At this point I realized that I had been putting the movement through a variety of paces for about two days (including leaving it to run overnight from Wednesday to Thursday, based on the theory that the movement needs to run for the oil to work its way through).

 

Unlike other Timex movements I've worked with, this one does not have a little window on the top of the movement that lets you inspect the mainspring, and the movement had wound down almost completely.

I wound it back up, and it worked like a charm!

[JerseyMo]

yes, sometimes the oil has to make its way around as you say.  Did you oil or grease the mainspring?  

 

[RichJensen]

56 minutes ago, JerseyMo said:

yes, sometimes the oil has to make its way around as you say.  Did you oil or grease the mainspring?  

 

No, according to the Timex manuals, it doesn't need oiling or greasing.

Here's the finished product:

 

[HectorLooi]

The 'dunk and swish' method only seems to work on Timexes and Dollar pocket watches. It still bothers me not to do a full strip down and clean for a Timex, but after being advised by JerseyMo and trying it out for myself, it does work 90% of the time. The times when it doesn't work is when there are other issues like worn out pivot holes.

Not bad for 50 year old disposable watches. 

[RichJensen]

50 minutes ago, HectorLooi said:

It still bothers me not to do a full strip down and clean for a Timex,

I wish I had the setup and experience to do more intensive work like that. As it is, I feel more like I'm sort of hanging around the fringes of actual watch repair.

[JerseyMo]

13 hours ago, RichJensen said:

No, according to the Timex manuals, it doesn't need oiling or greasing.

Here's the finished product:

 

 

Well, the manual is only a guide is all I will say after 15 years at Timex repair.

[JerseyMo]

10 hours ago, RichJensen said:

I wish I had the setup and experience to do more intensive work like that. As it is, I feel more like I'm sort of hanging around the fringes of actual watch repair.

Time and patience is the key to all tinkering.