2004 DAEWOO LACETTI brake

AISIN AUTOMATIC TRANSAXLE 5A2 – 201
DAEWOO V–121 BL4
Upper Valve Body
1. Sleeve
2. Key
3. Spring
4. Plunger
5. Lock–up Control Valve
6. Plug
7. Key
8. Secondary Regulator Valve
9. Spring
10. No.2 Check Valve
11. Key
12. Ball
13. No.1 Check Valve
14. Reverse Control Valve
15. Spring
16. Key17. Plug
18. Spring
19. 3–4 Shift Valve
20. Spring
21. O–ring
22. Reverse Clutch Accumulator Piston
23. O–ring
24. Plunger
25. 3–4 Shift Timing Valve
26. Spring
27. O–ring
28. 2nd Brake Accumulator Piston
29. O–ring
30. Spring
31. Upper Valve Body Cover

5A2 – 202IAISIN AUTOMATIC TRANSAXLE
DAEWOO V–121 BL4
Upper Valve Body Spring
S During reassembly, please refer to the spring specifications below to help you do discriminate between the differ-
ent springs.
MarkName (Color)Free length/Outer diameter mm
(in.)Total number of
coils
A3–4 shift timing valve (Pink)28.41 (1.1185) / 6.4 (0.252)10.49
B2nd brake accumulator piston,(None)
Inner45.90 (1.8071) / 10.5 (0.413)16.9
C2nd brake accumulator piston,(White)
Outer69.00 (2.7165) / 16.0 (0.630)15.1
DReverse clutch accumulator piston
(None)65.40(2.5748) / 17.0 (0.669)13.7
E3–4 shift valve (Red)25.50 (1.0039) / 9.73 (0.3831)7.75
FSecondary regulator valve (White)34.56 (1.3606) / 8.8 (0.346)12.27
GReverse control valve (None)25.58 (1.0071) / 8.64 (0.3402)8.75
HLock up control valve (Yellow)20.87 (0.8217) / 5.55 (0.2185)11.15

AISIN AUTOMATIC TRANSAXLE 5A2 – 221
DAEWOO V–121 BL4
HYDRAULIC CONTROL SYSTEM
Based on the hydraulic pressure created by the oil pump, TCM sends signals to solenoid and hydraulic control system
governs the hydraulic pressure acting on the torque converter, planetary gear, clutches and brakes in accordance with
the vehicle driving conditions.

5A2 – 222IAISIN AUTOMATIC TRANSAXLE
DAEWOO V–121 BL4
AUTOMATIC TRANSAXLE SYSTEM
Function of Components
ComponentFunction
C1Forward ClutchConnects input shaft and front sun gear.
C2Direct ClutchConnects input shaft and planetary carrier.
C3Reverse ClutchConnects input shaft and rear sun gear.
B1O/D & 2nd BrakePrevents rear planetary sun gear from turning either clockwise
or counterclockwise.
B22nd BrakePrevents outer race of F1 from turning either clockwise or coun-
terclockwise, thus preventing the rear sun gear turning conter-
clockwise.
B31st & Reverse BrakePrevents planetary carrier from turning either clockwise or
counterclockwise.
F1No.1 One–way ClutchWhen B2 is operating, this clutch prevents rear sun gear from
counterclockwise.
F2No.2 One–way ClutchPrevents planetary carrier from turning counterclockwise.
Planetary GearThese gears change the route through which driving froce is
transmitted, in accordance with the operation of each clutch
and brake, in order to increase or reduce the input and output
speed.

AISIN AUTOMATIC TRANSAXLE 5A2 – 223
DAEWOO V–121 BL4
Operations of Clutches and Brakes
Clutch & BrakeOperation
C1Forward ClutchConnects intermediate shaft and front sun gear.
C2Direct ClutchConnects input shaft and Planetary carrier.
C3Reverse ClutchConnects intermediate shaft and rear sun gear.
B1O/D & 2nd BrakeLock rear sun gear
B22nd BrakeLock rear sun gear
B31st & Reverse BrakeLock Planetary carrier
F11way Clutch No.1Lock counterclockwise rotation of rear sun gear, when B2 op-
erations
F21way Clutch No.2Lock counterclockwise rotation of planetary carrier

5A2 – 224IAISIN AUTOMATIC TRANSAXLE
DAEWOO V–121 BL4
PositionSolenoidClutchBrakeOne–way
Clutch
Shift 1Shift 2TimingC1C2C3B1B2B3F1F2
PONONOFFOFFOFFOFFOFFOFFOFFOF
–FOF
–F
RV<9
Km/
hONONOFFOFFOFFONOFFOFFONOF
–FOF
–F
V
9K
m/hONONONOFFOFFOFFOFFOFFOFFOF
–FOF
–F
NONONOFFOFFOFFOFFOFFOFFOFFOF
–FOF
–F
D1stONONOFFONOFFOFFOFFOFFOFFOF
–FON
2ndONOFFOFFONOFFOFFOFFONOFFONOF
–F
3rdOFFOFFOFFONONOFFOFFONOFFOF
–FOF
–F
(3
4)OFFONON
OFFON
OFFONOFFOFF
ONONOFFOF
–FOF
–F
4thOFFONOFFOFFONOFFONONOFFOF
–FOF
–F
21stONONOFFONOFFOFFOFFOFFOFFOF
–FON
2ndONOFFOFFONOFFOFFONONOFFONOF
–F
3rdOFFOFFOFFONONOFFOFFONOFFOF
–FOF
–F
11stONONOFFONOFFOFFOFFOFFONOF
–FON
2ndONOFFOFFONOFFOFFONONOFFONOF
–F

AISIN AUTOMATIC TRANSAXLE 5A2 – 225
DAEWOO V–121 BL4
D–1st Gear
PositionSolenoidClutchBrake1 way
Clutch
Shift 1Shift 2TimingC1C2C3B1B2B3F1F2
D1stONONOFFONOFFOFFOFFOFFOFFOF
–FON
11stONONOFFONOFFOFFOFFOFFONOF
–FON
”D” – 1st Gear
1. Input shaft rotates clockwise.
S Forward clutch (C1) operates. (Connect input shaft to front sun gear)
2. Front sun gear rotates clockwise.
3. Planetary short pinion rotates itself counterclockwise.
4. Planetary long Pinion rotates itself clockwise.
5. Planetary carrier is going to rotate counterclockwise.
S One way clutch No.2(F2) operates. (Lock revolves counterclockwise of planetary carrier)

5A2 – 226IAISIN AUTOMATIC TRANSAXLE
DAEWOO V–121 BL4
6. Ring gear rotates clockwise.
7. Counter drive gear rotates clockwise for ring gear and one.
8. Counter drive gear rotates counterclockwise
9. Differential gear drive pinion rotates counterclockwise for counter driven gear and one.
10. Differential gear rotates clockwise.
( Engine Brake)
1. Counter drive gear and Planetary ring gear rotates counterclockwise.
2. Planetary long pinion rotates itself counterclockwise.
3. Planetary short pinion rotates itself clockwise.
4. Planetary carrier revolves clockwise due to rotation itself counterclockwise of planetary long pinion, but driving
force loses due to free of 1 way clutch NO.2 (F2). Therefore Engine brake does not operate.