Seiko 4F56A, 8F56A, 8F58A Technical Manual
PARTS CATALOGUE / TECHNICAL GUIDE
Cal. 4F56A, 8F56A, 8F58A
[SPECIFICATIONS]
Cal. No.
Item
Movement
Movement
size
Time indication 3 hands (hour, minute and second hands) + 24-hour hand
Driving system
Additional mechanism
Outside diameter
Casing diameter
Height
Including the
(
battery portion
ø18.5 x 17.7 (3H - 9H) x
)
• Calendar (Leap year indication, month and date)
• Independent adjustment of hour hand
• Train wheel setting device
•Electronic circuit reset switch
• Battery life indicator
4F56A 8F58A
18.5 (12H - 6H)
17.1 (3H - 9H)
4.8
• Step motor (for 24-hour, hour, minute and second hands)
• Ultrasonic motor (for calendar indication)
Perpetual calendar up to February 28, 2100
8F56A
ø26.4 x 25.6 (3H - 9H) x 25.6 (12H - 6H)
24.8 (3H - 9H) x 24.8 (12H - 6H)
4.8
(x 1.0)The illustrations refer to Cal. 8F56A.
Loss/gain Annual rate within normal temperature range: less than 20 seconds
Regulation system
Measuring gate by quartz tester Use 10-second gate.
Battery
Battery No.
Voltage 3.0 V
Battery life Approx. 5 years
Jewels
Logical regulation (Pattern cutting system: 3 steps)
CR1612
4 jewels
BR2412
Approx. 8 yearsApprox. 10 years
1
PARTS CATALOGUE
Disassembling procedures Figs.: 1 fi 49
Reassembling procedures Figs.: 49 ‹ 1
Lubricating: Types of oil Oil quantity
Moebius A Normal quantity
Moebius V
Moebius F
Cal. 4F56A, 8F56A & 8F58A
Ex. : Cal. 8F56A
Cal. 4F56A, 8F56A, 8F58A
1 24-hour, Hour, Minute and
second hands
Please see the remarks on the following pages.
2Dial
3 Holding ring for dial
0884 167 (4F56A)
0884 166 (8F56A,8F58A)
2
PARTS CATALOGUE
Note Pull out the crown to the first click before starting disassembling or reassembling.
Cal. 4F56A, 8F56A, 8F58A
It is highly recommended that the exclusive
movement holder (S-680) be used for
disassembly or reassembly. Contact SEIKO
SERVICE CENTER to purchase this tool.
4 Battery
For removing or installing the
battery and inputting calendar data,
refer to page 11 to 16.
2 Battery
5 Insulator for battery (A)
A battery with 5 Insulator for
battery (A) (red) may be installed in
some models. Discard this type of
battery after replacing it with a new
battery of the latest model, to which
the insulator for battery (white) is
attached.
Insulator for battery(B) (white)
( + )
( - )
Cal. 4F56A, 8F56A & 8F58A
Ex. : Cal. 8F56A
4 Battery
5Insulator for battery (A)
6 Circuit block cover screw
0016 704
7 Circuit block cover
0016 704
• Circuit block cover screw (4 pcs.)
• Train wheel bridge screw (2 pcs.)
0016 705
• Ultrasonic motor screw (2 pcs.)
Please see the remarks on the following pages.
8 Circuit block
4003 424 (4F56A)
4003 091 (8F56A,8F58A)
9 Date driving
contact point spring
4281 115
10 24-hour contact point spring
4281 119
11 Battery connection (–)
4270 415
12 Insulator for battery (B)
4216 116
13 Coil block
4002 115
3
PARTS CATALOGUE
Cal. 4F56A, 8F56A & 8F58A
Ex. : Cal. 8F56A
Note Never remove the 24-hour
wheel and date driving wheel
while working on the date dial
replacement(without
disassembling the train wheel
side), as the date driving
contact point spring and 24hour contact point spring may
drop off.
Cal. 4F56A, 8F56A, 8F58A
14 Date dial guard 0808 127
15 24-hour clutch wheel
0273 113
16 Dial Washer
0491 016
17 Date dial
18 Hour wheel
0273 114
19 Intermediate 24-hour driving
wheel and pinion
0817 117
20 Third intermediate wheel for
hour corrector
0168 014
21 Date jumper screw
0012 354
0012 354
Date jumper screw ( 4 pcs. )
Please see the remarks on the following pages.
22 Date jumper
0810 116
23 Calender Plate
0195 014
24 Second intermediate wheel for
hour corrector
0168 013
25 Intermediate date driving wheel
and pinion
0817 118
26 Bush for second intermediate wheel
for hour corrector guide
4247 018
27 Ultrasonic rotor
4062 117
28 24-hour wheel
1019 114
29 Date driving wheel
0802 116
4
PARTS CATALOGUE
Cal. 4F56A, 8F56A, 8F58A
Cal. 4F56A, 8F56A & 8F58A
Ex. : Cal. 8F56A
30 Train wheel bridge screw
0016 704
31 Train wheel bridge
0125 254
32 Fourth wheel and pinion
33 Third wheel and pinion
0231 116
34 Fifth wheel and pinion
0701 116
35 Rotor
4146 116
36 Setting wheel
0281 115
37 Yoke guard
0388 116
38 Train wheel setting lever
0391 115
39 Stator
4239 115
40 Minute wheel and pinion
0261 048 (4F56,8F56A)
0261 049 (8F58A)
41 Setting lever
0383 115 (4F56A)
0383 116 (8F56A,8F58A)
42 Yoke
0384 116
Please see the remarks on the following pages.
43 Setting stem
44 Clutch wheel
0282 117
45 First intermediate wheel for hour
corrector
0168 011
46 Center wheel and pinion
47 Ultrasonic stator unit screw
0016 705
48 Ultrasonic stator unit
4234 115
49 Main plate
0100 148 (4F56A)
0100 138 (8F56A,8F58A)
5
PARTS CATALOGUE
Cal. 4F56A, 8F56A, 8F58A
Remarks
● Back plate
For some models which use the back plate, refer
to the illustration at the right to mount it.
● Case ring
The type of case ring is determined based on the
case design.
Check the case number and refer to “SEIKO
Casing Parts Catalogue” to choose the appropriate
case ring.
7 Circuit block cover
32 Fourth wheel and pinion
46 Center wheel and pinion
18 Hour wheel
Align the indicator to the
setting stem.
• Discrimination of the hand installation height
Cal. 4F and 8F Series watches have numerals printed on
movement to indicate the hand installation height. When
repairing, refer to the table below.
4F56A
Numeral for
discrimination
2
Circuit
block cover
4461 034
Center wheel and
pinion
0221 122
8F56A
Numeral for
discrimination
2
Circuit
block cover
4461 026
Center wheel and
pinion
0221 122
Numeral for discrimination
Fourth wheel and
pinion
0241 167
Fourth wheel and
pinion
0241 167
Hour wheel
0273 114
Hour wheel
0273 114
6
PARTS CATALOGUE
8F58A
Cal. 4F56A, 8F56A, 8F58A
Numeral for
discrimination
2
17 Date dial
Cal. No.
4F56A
8F56A
8F58A
The type of date dial is determined based on the case design.
* Not all the types of date dial are shown in the table above.
Check the case number and refer to “SEIKO Casing Parts Catalogue” to choose the appropriate date dial.
Circuit
block cover
4461 035
Part code
0878 320
0878 356
Center wheel and
pinion
0221 124
Position of crown and
calendar frame
3 o'clock
3 o'clock
Fourth wheel and
pinion
0241 167
Color of figure
Black
Black
Hour wheel
0273 114
Color of
background
White
White
43 Setting stem 0351 196
The type of setting stem is determined based on the case design.
Check the case number and refer to “SEIKO Casing Parts Catalogue” to choose the appropriate setting
stem.
7
Cal. 4F56A, 8F56A, 8F58A
TECHNICAL GUIDE
• The explanation here is only for the particular points of Cal. 4F56A, 8F56A and 8F58A.
• For repairing, checking or measuring procedures, refer to the “TECHNICAL GUIDE, GENERAL
INSTRUCTIONS”.
I. STRUCTURE OF THE CIRCUIT BLOCK
[ Cal. 4F56A ]
“M” terminal (for month setting)
“ø” terminal
(for resetting the date dial)
[ Cal. 8F56A, 8F58A ]
“ø” terminal
(for resetting
the date dial)
“M” terminal (for month setting)
“Y” terminal (for year setting)
AC terminal
“D” terminal
(for date setting)
“Y” terminal
(for year setting)
Input terminal (+)
C-MOS-IC
Crystal unit
C-MOS-IC
Input terminal (+)
Coil block output terminal
Input terminal (–)
Coil block output terminal
“D” terminal
(for date setting)
AC terminal
8
Crystal unit
Input terminal (–)
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