Page 2057 of 4179
OVERALL SYSTEM
AT-21
D
E
F
G
H
I
J
K
L
MA
B
AT
Circuit DiagramECS004QA
TCWA0228E
Page 2058 of 4179

AT-22
OVERALL SYSTEM
Shift MechanismECS004QD
CONSTRUCTION
FUNCTION OF CLUTCH AND BRAKE
1. Torque converter 2. Oil pump 3. Input shaft
4. Brake band 5. Reverse clutch 6. High clutch
7. Front sun gear 8. Front pinion gear 9. Front internal gear
10. Front planetary carrier 11. Rear sun gear 12. Rear pinion gear
13. Rear internal gear 14. Rear planetary carrier 15. Forward clutch
16. Forward one-way clutch 17. Overrun clutch 18. Low one-way clutch
19. Low & reverse brake 20. Parking pawl 21. Parking gear
22. Output shaft 23. Idle gear 24. Output gear
SAT998I
Clutch and brake components Abbr. Function
5 Reverse clutch R/C To transmit input power to front sun gear 7 .
6 High clutch H/C To transmit input power to front planetary carrier 10 .
15 Forward clutch F/C To connect front planetary carrier 10 with forward one-way clutch 16 .
17 Overrun clutch O/C To connect front planetary carrier 10 with rear internal gear 13 .
4 Brake band B/B To lock front sun gear 7 .
16 Forward one-way clutch F/O.C When forward clutch 15 is engaged, to stop rear internal gear 13 from rotating in
opposite direction against engine revolution.
18 Low one-way clutch L/O.C To stop front planetary carrier 10 from rotating in opposite direction against
engine revolution.
19 Low & reverse brake L & R/B To lock front planetary carrier 10 .
Page 2059 of 4179

OVERALL SYSTEM
AT-23
D
E
F
G
H
I
J
K
L
MA
B
AT
CLUTCH AND BAND CHART
*1: Operates when overdrive control switch is set in “OFF” position.
*2: Oil pressure is applied to both 2nd “apply” side and 3rd “release” side of band servo piston. However, brake band does not con-
tract because oil pressure area on the “release” side is greater than that on the “apply” side.
*3: Oil pressure is applied to 4th “apply” side in condition *2 above, and brake band contracts.
*4: A/T will not shift to 4th when overdrive control switch is set in “OFF” position.
: Operates.
A: Operates when throttle opening is less than 3/16, activating engine brake.
B: Operates during “progressive” acceleration.
C: Operates but does not affect power transmission.
D: Operates when throttle opening is less than 3/16, but does not affect engine brake. Shift positionRever
se
clutch
5High
clutch
6For-
ward
clutch
15Over-
run
clutch
17Band servo
Forward
one-way
clutch
16Low
one-
way
clutch
18Low &
revers
e
brake
19Lock-
upRemarks
2nd
apply3rd
releas
e4th
apply
PPA R K
POSITION
RREVERSE
POSITION
NNEUTRAL
POSITION
D*41st *1D B B
Automatic
shift
1 ⇔ 2 ⇔ 3 ⇔
4 2nd *1A B
3rd *1A *2C C B
*1
4th C *3C C
21stBB
Automatic
shift
1 ⇔ 2⇐3 2ndB
3rd *2C C B
11stB
Locks (held
stationary) in
1st speed
1 ⇐ 2⇐3 2ndB
3rd *2C C B
Page 2060 of 4179
AT-24
OVERALL SYSTEM
POWER TRANSMISSION
“N” and “P” Positions
“N” position
Power from the input shaft is not transmitted to the output shaft because the clutches do not operate.
“P” position
Similar to the “N” position, the clutches do not operate. The parking pawl engages with the parking gear to
mechanically hold the output shaft so that the power train is locked.
SAT991I
Page 2061 of 4179
OVERALL SYSTEM
AT-25
D
E
F
G
H
I
J
K
L
MA
B
AT
“11 ” Position
Forward clutch
Forward one-way clutch
Overrun clutch
Low & reverse brakeAs overrun clutch engages, rear internal gear is locked by the operation of low and
reverse brake.
This is different from that of D
1 and 21 .
Engine brake Overrun clutch always engages, therefore engine brake can be obtained when deceler-
ating.
SCIA1816E
Page 2062 of 4179
AT-26
OVERALL SYSTEM
“D1 ” and “21 ” Positions
Forward one-way clutch
Forward clutch
Low one-way clutchRear internal gear is locked to rotate counterclockwise because of the functioning of
these three clutches.
Overrun clutch
engagement conditions
(Engine brake)D
1 : Overdrive control switch “OFF” and throttle opening is less than 3/16
2
1 : Always engaged
At D
1 and 21 positions, engine brake is not activated due to free turning of low one-
way clutch.
SAT377J
Page 2063 of 4179
OVERALL SYSTEM
AT-27
D
E
F
G
H
I
J
K
L
MA
B
AT
“D2 ”, “22 ” and “12 ” Positions
Forward clutch
Forward one-way
clutch
Brake bandRear sun gear drives rear planetary carrier and combined front internal gear. Front internal gear now
rotates around front sun gear accompanying front planetary carrier.
As front planetary carrier transfers the power to rear internal gear through forward clutch and forward one-
way clutch, this rotation of rear internal gear increases the speed of rear planetary carrier compared with
that of the 1st speed.
Overrun clutch
engagement conditionsD
2 : Overdrive control switch “OFF” and throttle opening is less than 3/16
2
2 and 12 : Always engaged
SAT378J
Page 2064 of 4179
AT-28
OVERALL SYSTEM
“D3 ”, “23 ” and “13 ” Positions
High clutch
Forward clutch
Forward one-way
clutchInput power is transmitted to front planetary carrier through high clutch. And front planetary carrier is con-
nected to rear internal gear by operation of forward clutch and forward one-way clutch.
This rear internal gear rotation and another input (the rear sun gear) accompany rear planetary carrier to
turn at the same speed.
Overrun clutch
engagement conditionsD
3 : Overdrive control switch “OFF” and throttle opening is less than 3/16
2
3 and 13 : Always engaged
SAT379J