A 13 ligne day and date movement. It is the same as the Model 24 with a day and date mechanism added, so once the day frame assembly is off, the servicing is Model 24 servicing.
Hand-woundDay & Date13 LigneModel 24 Base
Factory Service Manual · Model 27 · Dial Side & Movement Side
Ligne13
Diameter28.96 mm
Diameter (inches)1.140 in
TypeHand-wound day & date
Built onModel 24 movement
SettingDay and date set manually
ManualService Manual · Model 27
Height5.50 mm
Jewels0
EscapementPin lever
Beat rate18,000 bph
Power reserve42 h
Height, jewels, escapement, beat rate and power reserve: ranfft.org
A Model 24 with a Calendar
The Timex Model 27 is a 13 ligne day and date movement. The Model 27 movement is the same as the Model 24 movement except that a day and date mechanism has been added. When the day frame assembly has been removed, basic servicing techniques are the same as for the Model 24. The day and date can be set manually.
Note: Because the Model 27 is a Model 24 underneath, disassembly, cleaning and reassembly of the base movement are covered in the Model 24 guide. This page covers what the Model 27 adds.
For the movement underneath, see the Model 24 exploded view.
Model 27 · Exploded View
145Dial Rest
242Cannon Pinion Assembly
255Hour Wheel
498/1Hour Wheel Washer
751Dial
850Hour Hand
851Minute Hand
852/1Sweep Second Hand
2557/1Date Ring
2561/1Day Frame Assembly
2573Day Detent Spring
2575Date Lever
2576Detent Spring
5145Pillar Screw
How the Indexing Works
1 · Date Ring Indexing
A finger integral with the date wheel on the underside engages and moves the date lever backward one tooth of the date ring.
At a pre-determined time the date lever is released, carrying the date ring forward one tooth.
A detent spring serves to prevent the date ring from backing up under shock, or when the date lever is being moved.
Fig. 27.3 · Date ring indexing
2 · The Date Lever and Detent Spring
The date lever, detent spring and date ring seen from the dial side.
Fig. 27.3 · Date lever & detent spring
3 · Day Ring Indexing
A finger integral with the date wheel on the top side engages the day pinion and moves the day ring.
A detent spring holds the day ring in position and also aids in moving the day ring.
Fig. 27.3 · Day ring indexing
4 · The Day Pinion and Date Wheel Finger
The date wheel finger engaging the day pinion. Use the exploded view as a guide in disassembly and assembly of the mechanism.
Fig. 27.3 · Day pinion
Cleaning & Lubrication
Lubricant change, June 1974: Timex Service Bulletin No. 111 replaced the factory oil for this model. Moebius Synt-A-Lube oil is used instead of Elgin M56B oil or Tenneco #415 oil. (It supersedes Bulletin No. 108.)
All cleaning and lubricating points indicated for the Model 24 should be followed for the Model 27. In addition, the underside of the dial rest, the underside of the day frame assembly and the date ring require lubrication. The dial rest and day frame assembly are lubricated while apart from the movement; the date ring must be lubricated when the mechanism is reassembled. Preferred oil is Elgin M56B, with Hamilton PML grease for the date ring and day frame detent spring.
Caution: Remember that the day and date ring actually are printed dials, and some watch cleaning fluids will strip the printing.
1 · Oil Points on the Movement
The oil points the calendar adds, marked on the movement side. Both sides where indicated.
Fig. 27.4 · Oil points
2 · The Day Frame Detent Spring
Grease at the junction of the day detent spring and the day pinion, applied while the day frame assembly is apart from the movement.
Fig. 27.4 · Day frame assembly
3 · The Date Ring
Grease on the date ring, applied when the mechanism is reassembled.
Warning: Never lubricate the junction of the day pinion with the day frame, for this may cause a failure.
Fig. 27.4 · Date ring
Positioning the Hands
1 · To Position Hands for Proper Day and Date Change
Hold the watch assembly movement side up with the crown and stem at the three o’clock position. Pull out the crown and stem.
Rotate the crown and stem slowly and observe the date lever at the nine o’clock position. The date lever will then begin to move and a click will be heard.
After the click, rotate the crown slowly until the date lever snaps back. At this time stop rotating.
Finally, replace all hands at the 12 o’clock position.
Fig. 27.5 · Date lever position
This guide is based on the original Timex factory service manual for the Model 27 movement.
