1990 MITSUBISHI ECLIPSE Service Manual

AUTOMATIC TRANSAXLE - Transaxle Mechanism21-33
POWER FLOW
T GEAR (“D” and ‘2” ranges)
Short
DinionCarrier
IForward sun gear
IOne-way clutch
IAnn&s gear
Rear clutch
-1Long pinioniransfer
drive gear
, Idler gear
Transfer* driven gear
17!50057
rear clutch is actuated when the shift is in 1 st gear in the
“D”. “2” or “L” range, driving force is transmitted to the forward sun
gear which rotates in the clockwise direction.
ITherefore, torque is conveyed from the forward sun gear through the
short pinion (counterclockwise) and the long pinion (clockwise) to theannulus gear (clockwise) to achieve the reduction ratio of 1 st gear.
Since the long pinion’s shaft (that is, the carrier) tries to turn
/counterclockwise at this time, the one-way clutch prevents this to
provide for a sufficient amount of driving force to be transmitted to
.
the annulus gear.
,
This means that, because the carrier can turn clockwise, engine brakedoes not function when the shift is in
1 st gear in the “D” or the “2”
range.

_____--._- .21-34AUTOMATIC TRANSAXLE
- Transaxde Mechanism
1ST GEAR (“L” range)
Low/Reverse brake
Carrier
IShort pinion
I
Forward sungearAnnulus gear
ODeratina elements:&ear clkch. .--. _.-__.I*Low-Reverse brake
1
I>\\PRear clutchLong pinion
1750058When the shift is in
1st gear in the “L” range, the low reverse brake is
actuated to fasten the planetan/ gear carrier, so that the gear does not
turn in either direction.
.
This means that engine brake works when the shift is in 1 st gear inthe “L” range.
cNOTEThe power flow in
1 st gear in the “L” range is the same as it is in 1 st gear
in the “D” and “2” ranges.

2ND’ GEARAUTOMATIC
TRANSAXLE - Transaxle Mechanism21-35
Kickdown brake
I
Shon pinion
\Forward sun gear
1.//LT.//. , ,’ .‘,,i.:,;:.:‘.,.‘,\/
/
Annulus gearLong pinion
Rear clutch/Reverse sun gear
fharatinn damants:
-, IWI WUIUI IWickdown brakeI
.
c
Since the rear clutch and the kickdown brake are actuated when theshift is in
2nd gear in the “0” or the “2” range, driving force is
transmitted to the forward sun gear which rotates in the clockwise
direction,
Therefore, torque is conveyed from the forward sun gear through the
short and long pinions to the annulus gear, as in the case of 1 st gear.
--However, since the reverse sun gear is fastened by in the case of
2ndgear, the long pinion“walks” on the reverse sun gear in the direction
of arrow (A), causing the annulus gear to rotate faster (or more) than
in the case of 1 st
gear in proportion to the length that the long pinionhas “walked”.
The reduction ratio of
2nd gear is achieved in this way.
---

21-36AUTOMATIC TRANSAXLE - Transaxle Mechanism3RD GEAR
Forward
,sun gear
I, CarrierEndclutch
Front clutch
Reverse
Angear
17soo60
,When the shift is in
3rd gear in the “D” range, the rear clutch and the
front clutch are actuated. and other elements are all released.Therefore, driving force is transmitted from the forward sun gear and
the reverse sun gear.
Since the short and long pinions rotate in the same direction, they are
placed under a locked condition, causing the planetary gear set to
rotate as one unit.
lThis means that the engine rotation is directly connected, setting the
ratio between the input to and output from the planetary gear set to
1:1. The reduction ratio of 3rd gear is achieved in this way.Note that the end clutch is aotuated to provide for smooth shift
change to 4th gear.&

AUTOMATIC TRANSAXLE - Transaxle Mechanism21-37
‘EAR (Overdrive)
Kickdown brake
Long pinionCarrterEnd clutch
Reverse sun gear
AnLlus gear
175006l
When the shift is in 4th gear, the end clutch and the kickdown brake
are actuated, and driving force is transmitted from the input shaft
through to the planetary gear set to drive the
annulus gear (the output
flange) via the long pinion.
1
Since the reverse sun gear is fastened at this time, the long pinioniotates
whie revolving on the reverse sun gear in the same directiona?ihe
carrier.
The
annulus gear rotates more (Or faster) than in the case of 3rd gear
in proportion to the rotation of the long pinion. The gear ratio of
overdrive is achieved in this way.

21-38RNERSEAUTOMATIC TRANSAXLE - Transaxle Mechanism
Low/Reverse brakeLong pinion
\I
IFront clutchIReverse sun gearIAnnulus
l
IWhen the shift is in
reverse.gear, driving force is transmitted to the
reverse sun gear because the front clutch is actuated.-1
And the low reverse brake is also actuated, fastening the planetan/
gear set carrier. This means that the driving force is conveyed from
the reverse sun gear (clockwise) through the long pinion (counter-
clockwise) to the
annulus gear (counterclockwise).*
/
- ~~_~
Since the carrier is fastened at this time, the long pinion’s
fixed, causing the long pinion to function as an idler gear. The
counterclockwise rotation and reduction ratio of back gear are
obtained in this way.

AUTOMATIC TRANSAXLE - Transaxle Mechanism
PARKING MECHANISM
rking sprag (Annulus gear)Detent plateWanual control shaft)
Detent ball
17ooo7When the shift is in the “P” range, the parking pawl
paw1 cannot be moved upward, and the cam, while
engages with the parking sprag provided on outerpressing the spring, collides with the parking
paw1circumference of the
annulus gear to fasten theand the suppon, and is withheld in this condition. If
output shaft, preventing wheels from rotating. Inthe vehicle is moved even slightly in this condition,
other words, when the selector lever is set to thethe turning of wheels causes the
annulus gear to
“P” range, the detent plate and the parking spragturn as well. Since the cam is pressed in the
rod move in the direction of arrow, causing the camdirection of arrow, the parking pawl is pushed up as
on the parking sprag rod to push up the parking paw1a bottom of the sprag aligns with the parking sprag
to engage with the sprag.to engage with the sprag.
In case the parking paw1 collides against a crest of
the sprag, only the rod moves because the parkingIn this way, the parking mechanism eliminates any
chances of the vehicle from being idly moved.

21-40AUTOMATIC TRANSAXLE - Transaxle Mechanism
START SAFETY MECHANISM
Inhibitor switch
Manual control lever
--
Connector-7DN R
‘,T,i \ ! I
‘\FlI
\ L
,p
( /1750253
1750149
Internal Connection in the inhibitor Switch
,
Teh;ina’ P R N D 2 LConnected circuits1 The start safety mechanism ensures the safety
during the engine starting operation. When the
selector tever is in the position other than “P” or
“N”, the electrical circuit for starting the engine is
kept in the OFF state by the inhibitor switch.
Therefore, the engine does not start even if the
ignition switch is turned to the “START” position.Inhibitor switch is installed on the transaxle case
located at the upper end of the manual control shaft
and is interlocked with the manual control lever. By
shifting the selector to the
“P” or “N” range, the
electrical circuit inside the inhibitor switch is con-
nected to form the ignition circuit with which the
engine can be started. When the shift is in the
“R”range, the backup light lights up as the backup
lightcircuit is energized.
The inhibitor switch, in addition to the start safety
device, ‘also includes a circuit for detection of the
selector lever position, for sending signals to the
transaxle control unit.
011Transaxle control unit0
Transaxle control unit
Transaxle control unit0000Ignition switch “ON”
terminal6
Transaxle control unit0
Transaxle control unit
I
7) 161 ) 1 ( 1Transaxle control unit
I I I I I I IIignition switch “ST”
terminalStarter motor “S”
terminal
10Ignition switch “ON”terminal
Backup light