Service Manual · Heritage 1854

The Model 254

DYNABEAT Calendar · Model 253 Base

The DYNABEAT with a calendar. The Model 253 with a date mechanism added, and the date is changed by rotating the hands through 24 hours in either direction.

Electric Calendar 28,800 bph DYNABEAT
Model 254 movement, dial side and movement side
Model 254 · Dial Side & Movement Side
Ligne9¾ by 12¾
Dimensions22.1 by 28.7 mm
Basic movementModel 253
Beat28,800 per hour
Date settingHands through 24 hours, either way
ManualService Manual · Model 254
Height6.10 mm
Jewels3
Height and jewels: ranfft.org

A Calendar on the DYNABEAT

The Timex Model 254 is a 9¾ x 12¾ ligne high frequency electric calendar movement, the same as the Model 253 except that the calendar mechanism has been added. The date can be changed manually, either forward or backward, by rotating the hands through 24 hours.

Note: The movement underneath is the Model 253. See the Model 253 guide for the high frequency electric movement, its contact system, index train, cleaning and lubrication.
Caution: Since the watch contains permanent magnets, no attempt should be made to demagnetize it.
Timex Model 254, movement
Photo courtesy of ranfft.org

Exploded View

Everything below the numbered parts is the Model 253 movement.

Model 254 exploded view
Model 254 · Exploded View
145Dial Rest
206Center Wheel Assembly
498/1Hour Wheel Washer
751Dial
850Hour Hand
851Minute Hand
852/1Sweep Second Hand
2556Date Wheel Assembly
2557/1Date Ring
2558Hour Wheel Assembly
2576Detent Spring

Disassembly

Getting the movement out of its case first? Case types and dust seals →

1 · The Caseback and Cell

Insert a blade into the opening notch on the bezel and pry the caseback off. The locating tab on the caseback is used for orientation of the back during reassembly.

Remove the energy cell, then lift off the movement cover. The cover is held in place by two tabs which snap into recesses in the bezel.

Note: Any energy cell with a voltage of less than 1.5 volts, or one in service in excess of one year, should be replaced. Use of an energy cell not meeting Timex specifications may cause the watch to malfunction.
Caseback, locating tab, energy cell and bezel
Fig. 254.3 · Figure A
2 · The Movement Cover

The cover and the tab which snaps into the bezel, with the movement beneath.

The movement cover and its tab
Fig. 254.3 · Figure B
3 · Releasing the Stem

The stem is held in position by the stem bracket. Pull the stem out into the set position and continue to maintain a slight outward pull.

Place the points of a heavy tweezer into one side of the stem bracket and push the bracket aside to release one side of the stem. Continue to pull the stem outward and use the tweezer points to release the other side. The stem will now pull free of the movement and case.

Inserting tweezers at the stem bracket
Fig. 254.4 · Figures C and D
4 · Out Through the Crystal

After the stem is removed, the movement can be removed through the crystal side of the case. Remove the crystal with a crystal seating tool and then lift the reflector ring and movement free of the case.

Note: Note the position of the movement locating tabs inside the bezel. Tabs should align in the notches of the plate when reassembling.
Crystal, reflector ring, movement and bezel
Fig. 254.4 · Figure E
5 · The Calendar Stack

Remove the sweep second hand and the minute hand. Bend the four dial tabs enough to free the dial from the movement.

Turn the assembly over and carefully lift the dial off the movement. Note the position of the parts under the dial: the detent spring which positions the date ring, and the finger on the date wheel which indexes the date ring, shown in its position following the date change.

Lift off in order: date ring, date wheel assembly, center wheel assembly, detent spring, noting its engagement in the dial rest.

Caution: With these parts removed the movement may be serviced as for the Model 253. Extreme care must be exercised when cleaning dials, hands and date rings; solvent type cleaners may damage the finish.
Detent spring, dial rest, date ring, date wheel and center wheel
Fig. 254.5 · Figure F

Reassembly

Replace the detent spring in the dial rest.

Assemble the date ring, deflecting the end of the detent spring until it engages a tooth of the date ring.

Position the finger of the date wheel next to the date ring tooth as shown in the figure above.

Lubricate the date wheel post and the end of the detent spring where it engages the date ring, using non-spreading oil; Moebius Synt-a-lube is used in the factory.

1 · Replace the detent spring in the dial rest
2 · Assemble the date wheel assembly
3 · Assemble the date ring, deflecting the end of the detent spring until it engages a tooth
4 · Position the finger of the date wheel next to the date ring tooth as shown above

Dial Rest Lubrication

Timex Service Bulletin No. 112 · July 1976
Applying lubricant between 3 and 6 o’clock to the inside corner of the Model 254 dial rest

The solid film lubricant has been eliminated from the dial rest on the Model 254 watches. These watches should be lubricated by applying a spreading type lubricant (Woods AAAA oil is used in the factory) between 3 and 6 o’clock to inside corner of dial rest.

This same lubricant may be applied to dial rests which have solid film lubricant (i.e. Models 41, 51, 62 and 254).

Positioning the Hands

1 · First

First: check that the finger on the date wheel is positioned against a date ring tooth as shown in the figure above.

2 · Next

Next: replace the dial assembly holding the hour hand at the 2 o’clock position, making certain the hour wheel teeth engage the minute pinion teeth, and bend the four dial tabs to hold the assembly firmly in position.

3 · Finally

Finally: replace the minute hand and sweep second hand.

Check: Insert the crown and stem assembly and rotate the hands clockwise to assure the date change is completed by 2 o’clock.

Remove the crown and stem assembly. Place the assembly into the bezel, being sure the notches in the plate engage the tabs inside the bezel. Position the reflector ring on top of the dial and insert the crystal using a crystal insertion tool. Insert the crown and stem assembly through the bezel with a twisting motion to assure engagement in the bracket.

Insert the movement cover and snap it into the bezel. Insert a fresh Timex Type A energy cell and snap the caseback into position. Push the crown in and the watch will start immediately; if not, slight finger agitation may be necessary.

Cells: Use of an energy cell not meeting Timex specifications may cause the watch to malfunction. Do not dispose of an energy cell in fire.

This guide is based on the original Timex factory service manual for the Model 254 movement.

6 pages · 1 PDF

Model 254 PDF