2004 DAEWOO LACETTI aisin automatic transaxle

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.

AISIN AUTOMATIC TRANSAXLE 5A2 – 227
DAEWOO V–121 BL4
D–2nd Gear
PositionSolenoidClutchBrake1 way
Clutch
Shift 1Shift 2TimingC1C2C3B1B2B3F1F2
D2ndONOFFOFFONOFFOFFOFFONOFFONOF
–F
22ndONOFFOFFONOFFOFFONONOFFONOF
–F
”D” – 2nd 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. Rear planetary sun gear is going to rotate counterclockwise.
S 2nd brake (B2) and 1way clutch No.1 operates. (Lock counterclockwise rotation of rear planetary sun gear)

5A2 – 228IAISIN AUTOMATIC TRANSAXLE
DAEWOO V–121 BL4
6. Planetary carrier revolves clockwise due to reaction force of planetary long pinion.
7. Ring gear rotates clockwise.
8. Counter drive gear rotates clockwise for ring gear and one.
9. Counter driven gear rotates counterclockwise
10. Differential gear drive pinion rotates counterclockwise for counter driven gear and one.
11. 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. Rear sun gear rotates clockwise due to rotation itself counterclockwise of planetary long pinion, but driving force
loses due to free of 1 way clutch No.1(F1). Therefore Engine Brake does not operate.