I posted the first look at this clock a while back.
The Regency style veneered mahogany case of this Junghans time and strike bracket clock is in reasonably good shape save for a small piece of veneer missing on the front right corner and replacement chrome feet which look decidedly out of place.
The movement ran briefly after I got it home but after a short while refused to run despite adjustments. The seller says he had had the clock for two years and never had it running so I was sure it needed a good cleaning. In any event, my plan was to service the movement.
The movement is has a maker’s mark with B11 just below it. This refers to the approximate date of manufacture, the latter part of 1911.
Removing the movement
To remove the movement remove the hands, first the minute and then the hour hand. Open the rear access door to release two thumbscrews screws underneath the movement seat board. Move the gong assembly aside (or take it out completely by releasing a screw on the bottom of the case) and remove the works.
Assessing the movement
This is a well-made movement. Early Junghans movements were robust and strong runners. I have heard stories of Junghans clocks from this era running well despite being very worn. Junghans’s movements are a cut above Mauthe, Hermle, HAC, and other mass-produced German clocks made during this period, in my view. The movement exudes quality with solid front and back plates though lantern pinions are favoured over cut pinions.
The movement has been serviced at least once, so far as I can determine. There is an “S” mark on the strike side barrel cap, helpful when returning the barrels to their correct location. I did not measure the mainsprings but the strike side spring is notably longer than the time side. There are two possible reasons, one that the strike side mainspring was replaced at some point in the clock’s life, or two, there is more load on the strike side requiring a stronger spring.
The mainsprings are in good condition and there is plenty of power though there is more oil than necessary within the barrels. After assessing the movement I could see that there had been no significant repairs in the past. The crutch has been bent in several places in an attempt to adjust the beat but otherwise, everything looks reasonably good for the age of the clock.
Separating the plates was more difficult than it should have been. I had to remove all four pillars (secured by screws on both ends) to determine what was sticking. I discovered that the motion works centre arbour pivot was “stuck” in the backplate. By “stuck” I mean that although the wheel was moving freely the end of the pivot had been flattened. Why I don’t know. Had the pivot been punched in an attempt to enlarge it, had someone hammered the pivot end for whatever reason, had the pivot been replaced or it is possible that the plates had never been separated and that is how it came from the factory? Once the pivot was pried from the plate I rounded the end with a file and it now fits perfectly.
All parts were cleaned in the ultrasonic cleaner which removed a considerable amount of accumulated grime. As always the ultrasonic cleaner does a great job with lantern pinions and the lantern pinions, on all 6 wheels, are in excellent condition.
There has been no bushing work done on the movement. The only punch mark I observed was just below the escape wheel outside the plate where an attempt was made to close the hole.
To bush or not to bush
After cleaning the movement, pegging the holes, and polishing the pivots the next step is deciding whether or not to bush the movement.
I could see that some bushings may be required, 4 on the backplate where there is more load on the wheels and 2 on the front plate for a total of 6, 2 on the strike side, and 4 on the time side but I will make a final decision once I have checked the entire movement further.
I installed all the wheels and checked for pivot movement within their respective pivot holes. The wear was not excessive. However, after much thought, I decided there is enough lateral movement of the pivots in their holes to affect its running. Besides, I wanted to place the clock in a prominent area of the house and by addressing wear issues now the clock would run well for some time without another servicing.
Seven bushings were installed, 3 on the time side, and 4 on the strike side. The largest one, which I did not include in my initial assessment, was a 4.5mm (OD) bushing for the count wheel.
Re-assembly and testing
Once all the pivot work is complete and the holes pegged out again it is time for re-assembly. Setting up the strike side of the count wheel strike means ensuring that the warning pin is sitting just off the locking lever (12 o’clock position), the drop lever is sitting on the flat section of the cam wheel, and the count lever is in one of the deep slots of the count wheel.
Only this time it was not all roses. The strike train consistently missed the half-hour strike because the count lever would drop in the middle part, not the beginning of the deep slot, occasionally missing the half-hour strike. Plus, the count lever did not completely rest on the cam. I cannot remember spending as much time correcting the strike side on a German movement as I did on this one. On one occasion I had everything together to discover that the paddle was hanging off one of the points of the star wheel. Having too much load at the beginning of the strike either will stop the strike or add one more strike to the indicated hour.
I must have taken the movement apart 5 times, and of course, each time I reassembled the movement I was wary of damaging those tiny pivots. Eventually, everything worked out. Sometimes when working with German countwheel strikes everything falls into place the first time. Not so much this time.
While on the workbench, I replaced the old tired suspension spring with a new one.
So, after a long-overdue cleaning and a few new bushings, the movement is oiled and is on the test stand. After several small adjustments to the beat, it is now running and striking as it should.
Now to see how we can address a grimy silvered dial. Join me in a couple of weeks as I take you through cleaning the dial face.
2 thoughts on “Junghans bracket clock – servicing the movement”
Looking forward to face cleaning post!
Dec 21, 2020.
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