Seiko 8T67A Installer manual
PARTS CATALOGUE / TECHNICAL GUIDE
Cal.8T67A
8T67A
Driving system Step motor 2 pieces
Additional function
Crown Normal position Free
operation 1st click position Date setting (clockwise)
2nd click position Time setting, Resetting the circuit
Loss/Gain (Monthly rate) Less than 15 seconds at normal temperature range
Frequency of crystal oscillator 32,768 Hz
Operational temperature range
-5℃~ +50℃
Regulation system Nil
Gate time for rate measurement Use 10-second gate
Current consumption
Coil resistance
・4002054（Coil block A): 1.45 - 1.65KΩ for chronograph
・4002055（Coil block B): 1.65 - 1.85KΩ for time display
Power Battery No.
SR936SW (Silver oxide battery)
supply Battery voltage
1.55V
Battery life Approximately 3 years
Jewels
0 jewel
1/20
Cal. No.
Item
・Stopwatch function up to 12 hours in 1/5 second
・Date display with quick correction.
・Energy depletion forwarding function
(The second hand moves at two-second intervals.)
・Movement: Less than 2.7μA
・Circuit block: Less than 0.7μA
Movement Size
・Outside diameter: 30.8 mm
・Casing diameter 29.0 mm
・Height：5.1 mm
・3 Hands: Hour, Minute, and 1/5 second chronograph hand
・Small Second : Small second hand(6H), Minute chronograph hand (12H),
Hour chronograph hand(9H)
PARTS CATALOGUE
8T67A
Type of oil Oil quantity mark
AO-3(Moebius A）
NORMAL QUANTITY
AO-2(Moebius F) SUFFICIENT QUANTITY
S-6
0012 354
Date indicator maintaining plate screw
0808 052
Date indicator maintaining plate
Date indicator
0810 019
Date jumper
0806 002
Date corrector wheel
Intermediate date wheel and pinion
Date Indicator driving wheel
2/20
[ Cross section ]
5
6
0817 048
7
0802 039
1
2
3
Refer to page 7 for each parts code.
4
Disassembling procedures Figs.
1
→
62
Reassembling procedures Figs.
62
→
1
*1
*1
0103 448
Main plate
PARTS CATALOGUE
8T67A
0273 *** Refer to page 8 for each parts code.
Hour wheel
0012 354
Switch lever holder screw
0837 005
Switch lever holder
4450 017
Switch lever A
4450 018
Switch lever B
0962 891
0962 013
3/20
8
9
11
12
14
Date corrector setting
transmission wheel C
13
Date corrector setting
transmission wheel B
10
PARTS CATALOGUE 8T67A
0016 121
Switch spring screw
0016 121
Switch spring screw
16 4250 ***
Switch spring
Refer to page 8 for each parts code
and page 12 for spring setting position.
0353 018
Second counting wheel friction spring
0190 007
Chronograph bridge
0587 006
Refer to page 12 for 0581 007
spring setting position. Chronograph coupling lever
Refer to page 12 for
21
0585 013 spring setting position.
Hammer
Refer to page 10 for
oiling spot and page 12
for spring setting position.
0894 002
Train wheel stop lever
0888 *** Refer to page 12 for
Second countingwheel spring setting position.
Refer to page 8 for
each parts code.
23 0902 ***
Minute counting wheel
Refer to page 8 for
each parts code.
0587 004
Hammer operating lever A
Refer to page 12 for
24 0902 *** spring setting position.
Hour counting wheel
Refer to page 8 for
each parts code.
4/20
Hammer operation lever B
15
15
17
18
20
19
25
22
26
*1
*2
*1
*2
PARTS CATALOGUE 8T67A
0016 121
0186 002
Lower plate for chronograph bridge
Refer to page 10 for
oiling spot.
4408 149
Circuit block spacer
4004 352
0125 318
Circuit block
Train wheel bridge
4270 336
Battery connection (-)
*㉝～㊳
Refer to page 9 for assembling
of chronograph wheel.
0885 003
0012 354
0886 004
Coil block screw
4002 054
Coil block A
0886 005
4146 063
Step rotor
4239 063
0701 015
Stator A
Fifth wheel and pinion
5/20
38
0885 004
Hour counter intermediate
wheel and pinion A
42
43
36
Counter intermediate
wheel and pinion
40
37
Minute counter intermediate
wheel and pinion A
41
Hour counter intermediate
wheel and pinion C
35
Second counter intermediate
wheel and pinion
39
34
0885 005
Hour counter intermediate
wheel and pinion B
31
33
0885 006
32
27
28
Lower plate for chronograph bridge screw
29
30
*1
*1
PARTS CATALOGUE 8T67A
0231 059
Third wheel and pinion
4455 006
0144 002
Reset lever
Fourth wheel and pinion
0261 126
0391 028
Minute wheel and pinion Train wheel setting lever
0281 452
0012 354
Setting wheel
Coil block screw
4002 055
4283 042
Coil block B
4146 063
Step rotor
0221 ***
Refer to page 8 for
4239 064
each parts code. Stator B
0383 891
0701 015
0384 024
Yoke
0240 ***
Second wheel
0282 452
Refer to page 8 for Clutch wheel
each parts code.
0962 032
0351 177
Winding stem
6/20
45
44
46
47
55
51
48
52
Center wheel and pinion
53
49
Center wheel and pinion bridge
54
50
57
61
62
Date corrector
setting transmission
wheel A
60
58
Setting lever
56
Fifth wheel and pinion
59
*1
*1
PARTS CATALOGUE 8T67A
●Tools and consumables required for disassembling/reassembling
・Movement Holder
UNIVERSAL MOVEMENT HOLDER (S-682)
・Watch oils
SEIKO watch oil AO-2, AO-3 and S-6
AO-2 AO-3
S-6
7/20
TECHNICAL GUIDE 8T67A
Remarks:
●How to find the correct parts, if not determined by 4 digit caliber number.
Please refer to the following table in order to find the correct part number of each wheel according to the hand
installation height. The numeral 2 or 4 is printed on the DIAL.
Caliber code
8T6720A 8T6740A
No Parts name Parts code Parts code
⑧
Hour wheel
0273 038 0273 042
⑯
Switch spring
4250 088 (marking "2")
4250 090 Marking "4"
㉒Second counting wheel 0888 028 0888 029
㉓Minute counting wheel 0902 017 0902 018
㉔Hour counting wheel 0902 017 0902 018
㊿Center wheel and pinion 0221 087 0221 092
Second wheel 0240 018 0240 019
③Date indicator
Parts code
Crown Date Color of Color of
position Position figure background
0878 328 3H 3H Black White
0878 329 3H 3H White Black
* All parts code are subject to change without notice.
8/20
5
REMARKS ON DISASSEMBLING AND REASSEMBLING THE MOVEMENT
TECHNICAL GUIDE 8T67A
●How to assemble chronograph wheel
There is a mark on parts. Parts are set in order of the mark as shown in the table below.
Image example of the mark
Mark
Parts name
A38 Hour counter intermediate wheel and pinion A
B37 Minute counter intermediate wheel and pinion A
C36 Counter intermediate wheel and pinion
Nil
35 Second counter intermediate wheel and pinion
D34 Hour counter intermediate wheel and pinion B
E33 Hour counter intermediate wheel and pinion C
9/20
34
Hour counter intermediate
wheel and pinion B
35
Second counter intermediate
wheel and pinion
33
Hour counter intermediate
wheel and pinion C
36
Counter intermediate
wheel and pinion
38
Hour counter
intermediate
wheel and pinion A
37
Minute counter
intermediate
wheel and pinion A
TECHNICAL GUIDE
8T67A
Type of oil Oil quantity mark
AO-3(Moebius A）
NORMAL QUANTITY
AO-2(Moebius F) SUFFICIENT QUANTITY
S-6
●Remarks for the lubrication
Hammer
Lower plate for chronograph bridge
Note:
*1: Lubricate on the pointed spot.
16
Switch spring
Oiling spot and spring setting position are below;
Chronograph coupling lever
Hammer operating lever B
Setting position
Switch spring
10/20
16
*Lubricate on the contact spot of the spring and the pin.
21
19
20
27
*1 *1
*2
*3
*2
*3
*1
*1
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